This is real easy, no explanation required: Tell your student to stick their hand out the window of the car driving 25mph in the city and rotate it like an aileron.

Then have them do it on the freeway doing 60mph.

Feel the difference?

Did smaller movements produce larger effects at higher speeds?

Practical examples are typically more effective at driving a point home than a lot of words.

Very simply, because the dynamic pressure drops as you slow down, making all aerodynamic controls more sluggish.

Aileron works by locally increasing the lift of one outboard wing and decreasing the lift of the other, thereby creating a torque or rolling moment.

For simplicity, let's think that for every degree of aileron deflection, there is an associated increase and decrease in the local lift coefficient for TE down aileron and TE up aileron, respectively 1 .

You may remember that the total lift differential is proportional to the lift coefficient, but also to the dynamic pressure.

You may also remember that dynamic pressure is proportional to the square of the true airspeed.

Therefore, as you slow down, even though the lift coefficient differential remains more or less constant for the same aileron action, the total lift differential decreases as a square of the speed, and the same for the rolling moment.

The change in local lift coefficient is not constant across flight regime.

As the AOA increases toward stall, significant nonlinear effect arises.

To make the answer as simple as possible, an aerofoil will increase lift in two ways, either by going faster or increasing the angle of attack.

When the aileron moves up or down

it’s changing the shape of the wing and either increasing or decreasing the angle of attack.

So, if you fly fast just a small aileron deflection will produce the necessary lift to raise the wing.

Conversely, if the aerofoil is going slow the aileron will require a greater deflection to create a larger angle of attack for the same amount of wing movement.

Hence at high speeds the aircraft will feel very responsive and at low speeds will feel unresponsive particularly as it approaches stall speeds.

You should understand this is a very simple overview and there are many other aspects to consider.

The lift that is generated by an aileron at a fixed deflection (e.g. 5 degrees down) is proportional to the volume of air that is deflected downward per unit of time (e.g. per second).

As speed is reduced the volume of air being deflected downward per unit time is reduced so the lift created by the aileron is also reduced and the aileron become less effective.

In the flight envelope you describe, the aileron response is affected by two factors: the change in lift from the movement is related to thespeed of flight.

As the speed reduces, the force diminishes, and, when the wing stalls, airflow over the aileron is substantiallyturbulent and no usable effect results from aileron movement.

This applies equally to other aircraft, not just light trainers.

However, sophisticated fly-by-wire controls are often designed to not allow stalling and prevent the effect from being noticed under normal flight conditions.

why does aileron response decrease ...

from slow flight up to stall.

Yes, controls definitely get more sluggish slowing down from cruise speed to slow flight, due to the reduction of aerodynamic force on their area.

From slow flight to stall, with ailerons, one must be aware of additional effects beyond reduction in airspeed.

Ailerons work by moving one up and one down.

All well and good until one goes to higher angles of attack.

There is a loss of effectiveness for the upturned aileron due to flow separation approaching stall.

This is compensated by increased angle of attack of the downtrend aileron, but it will stall first.

This is the dreaded "aileron reversal" that can lead to a spin.

Note that in the PARE spin recovery method, ailerons are nuetral.

From slow flight to stall, use your rudder and turn coordinated to stay safe.

Easy - it's no different than the WHOLE WING exhibiting diminished response at low speeds!

When you pull back on the yoke, that IS because you are getting diminished response from the wing.

The ailerons likewise require more displacement for the same effect at low speeds compared to high speeds.

If the student then can't grasp why the whole wing doesn't work at slow speeds, then you at least have uncovered the level of the student's intuition and understanding!

Question: Can someone phrase the explanation to this in simple words as you would explain to a student?

Why does aileron response diminish as speed becomes slower, from slow-flight up to the stall? (In a light trainer)

Very simply, aileron response decreases as you slow down because the dynamic pressure drops as you slow down, making all aerodynamic controls more sluggish. Moreover, there is a loss of effectiveness for the upturned aileron due to flow separation approaching stall.

You might consider using examples to illustrate your point. The aileron response decreases as your speed becomes slower, because dynamic pressure, that is to say the amount of deflected air in simple terms, is reduced and all relevant controls stall. While the aileron angle is aimed at making up for flow separation while slowing down, the effect is not completely diminished.


By putting the guns on the side, the gunner can direct a continuous stream of bullets at the intended target for as long as the pilot wishes to continue circling it.

If the guns were belly-mounted, the pilot would have to make multiple passes at the target zone from different directions, with long pauses between them- long enough for the enemy soldiers to reposition themselves and escape.

The C130 is a cargo aircraft.

The AC130 is the airframe converted for use as a gunship, of which there are several variants.

Guns under an aircraft are usually found on helicopters, mounted on turrets.

Purpose built aircraft usually integrate guns into the wings (fighters) or fuselage (A10).

WW2 bombers like the Flying Fortress worked more like the AC130, and had gunners in various places including a belly mounted turret.

The low load floor of a cargo aircraft precludes placement of guns there.

Additionally, the AC130 carries multiple guns .

7.62 Minigun, 25mm Gatling gun, 40mm Bofors cannon, and 105mm howitzer have all been used.

Simultaneous use requires multiple mounting points.

Same side placement means they can all be used on one target.

The original concept of the AC-130 gunship was to loiter over an area for an extended period of time in support of ground troops.

It provides close air support when precision is needed instead of indiscriminate strafing runs of fast movers like F-4s and other jets.

Using a ground reference maneuver called turns on pylons and pivotal altitude keeps one side of the gunship perpetually aligned with a target on the ground as the aircraft circles it.

You can find more detail on the Smithsonian Channel

show Air Warriors .

Because the AC-130 is an airplane, not a helicopter, the only way to "hover" over a target is to fly in a circle around the target.

This is called "loitering".

This is the primary use-case for the AC-130: it's basically a flying artillery position, not a flying tank.

Having guns point downwards will have the guns point away from the target (due to banking)

when loitering.

Making it unsuitable to be used as a flying artillery position and forcing it to behave like a bomber (flying, reusable "bullet/shell"*).

I think you've got this the wrong way round - you don't fly in circles because the guns are on the side; the guns are on the side because you have to fly in circles.

The only way to get a fixed-wing aircraft to loiter over a particular spot is for it to fly in a circle.

To do this you have to bank

the aircraft (i.e., tilt it on its side).

If you do this, you automatically present the side of the aircraft to the target, so it's the natural place to position your guns.

If you put them on the belly, you'd have to then aim them to the side - as far as they would go.

This side-firing strategy grew out of a technique developed by the British Chindits in Burma in WW2.

They used small fixed-wing aircraft for supply and evacuation.

The planes could not land in the jungle, so flew tight orbits over a clearing and lowered supplies on a rope.

They then hauled up casualties the same way.

In the Vietnam War, the Americans had the idea of replacing the rope with a line of fire and the gunship was born.

Question: Why must the guns of the AC-130 be on the side forcing the plane to circle the target. Would it not be more practical to have the guns underneath the plane shooting downwards?

Why are the guns on the AC-130 not mounted on the underside of the aircraft?

If the guns were belly-mounted, the pilot would have to make multiple passes at the target zone from different directions, with long pauses between them- long enough for the enemy soldiers to reposition themselves and escape.  Because the AC-130 is an airplane, not a helicopter, the only way to "hover" over a target is to fly in a circle around the target.  iin fact, purpose built aircraft usually integrate guns into the wings (fighters) or fuselage (A10).

Mounting the guns on the underside of the aircraft would have them point towards the ground and away from the enemy. In this context, the pilot would need to approach the target from many directions. The AC-130 in particular is specially designed to mount guns on the side, aiming to keep them aligned with the target while flying.

The AC-130 is specially designed to mount guns on the side, aiming to keep them aligned with the target while flying.


Wikipedia article on "offside" is very comprehensive and largely based on the official IFAB Laws of the Game.

From the article, what it is: Offside is a law in football which states that if a player is in an offside position when the ball is touched or played by a teammate, he may not become actively involved in the play.

A player is in an offside position if he is closer to the opponent's goal line than both the ball and the second-to-last defender (which is usually the last outfield player), but only if the player is on his opponent's half of the pitch.

How it is officiated: In enforcing this rule, the referee depends greatly on an assistant referee, who generally keeps in line with the second-to-last defender, the ball, or the halfway line, whichever is closer to the goal line of his relevant end.

An assistant referee signals that an offside offence has occurred by first raising his or her flag upright without movement and then, when acknowledged by the referee, by raising his or her flag in a manner that signifies the location of the offence

So in my own simple words, you determine an offside by:

At the time when the ball is played (pass or kick down the field) note where the second last defender (usually the last defender as the goalkeeper is usually furthest back of any, but not always!)

of the defending team is and where is the player(s) of the offending team (who are involved in the play*)

are further down the field from the ball

Draw a line parallel to the base line (goal line) of the pitch through the said players

If you see that the line going through an offending player who is about to receive the ball is closer to the goal than the line going through the last defender, and that line is in the defending half, then it is an offside. by "involved in the play" we mean that they are likely to either receive the ball as a result of the pass in question or are able to influence the outcome of the play in some other way.

A player would not be considered involved if he is on the other side of the pitch with the ball going away from him.

Refer to the Laws of the Game for more info.

Notice that there are a few exceptions when someone can be or not be offside.

When a ball is brought back into play after it left the pitch, one can never be offside.

So, one can never be offside after directly receiving a ball from a throw-in, goal kick, corner kick or a kick off (of which the latter two are rather trivial).

From a (indirect) free kick one can be called offside, since the ball had not left the pitch.

Suppose someone shoots for goal while his teammate is in offside position.

When the ball then returns from the post, the bar or even the goalkeeper and comes in the possession of the teammate, he is still offside.

Offside is not bounded by the lines of the pitch.

So, one can still be offside or prevent an opponent from being offside while being out of play.

See gbianchi's answer to this relevant question .

A Picture is worth thousand words!

Hope this helps you understand

I've noticed that football players often talk about being level with the second last defender; but the FIFA offside rule is now much more precise.

At the instant the ball leaves the attacking player the offside vertical plane is fixed at the part of the second defender (other than his arms) which is closest to the goal line.

At that instant, if any part of another attacking player has any part of their body (except the arms)

beyond that plain they are potentially offside.

A couple of quick additions, which I have not seen mentioned in previous answers (it's late and I am very tired

so I might have missed, if that's the case I'll remove this answer)

There is a scenarios which might be confusing; a player is not off-side if; beyond the second lass defender but the pass to him comes from a team mate that is further ahead of him i.e. if the pass is backwards (similar to rugby)

There is a pretty nice guide which explains the concept in detail, with illustrations.

A bit stupid to make this an answer

but it's not yet (completely correct) on here.

And I can not comment yet, so here goes:

In addition to posdef's answer: you can be in an offside position if a player passes backwards as much as with a forward pass.

As long as the player stays behind his teammate it does not matter in which direction the pass is given.

But if he is in front of his teammate and gets the pass played at him in backward direction he is still in an offside position.

I used to help ref soccer games when I was younger and the way I was taught to call the off-sides penalty was that if the player on offense was beyond the last defender (goalie doesn't count obviously) before the ball was also beyond the last defender, then the player is off-sides.

Some people (myself included) think the way it should be called is that the player on offense needs to be even with the defender, but should be allowed to pursue the ball as soon as it is passed to them, regardless of their position relative to the other teams defensive players.

In other words - let one players speed and instinct give them an advantage - rather than a penalty.

Question: The offside rule on the pitch is often unclear and called suddenly. How do I know if a player is offside?

How is offside determined in football?

A player is in an offside position if he is closer to the opponent's goal line than both the ball and the second-to-last defender (which is usually the last outfield player), but only if the player is on his opponent's half of the pitch.

Football defines offside as the position of a player closer to the opposing goal post than the ball and the other team's last defender, not including the goalkeeper. Any player in an offside position should not participate in the game actively. Offside may apply for indirect kicks, both for forward and backward passes.


This is mostly to encourage more at bats to end with a ball in play.

Baseball is most exciting when a batter can put a ball in play.

It also gives the batter a slight advantage in that he can continue to foul pitches that he cannot achieve solid contact with and "keep himself alive.

This balances the pitcher's competitive advantage of knowing where the ball is going, how fast its traveling and what kind of pitch is being thrown.

In 0 and 1 strike counts the strike on a foul rule exists to advance the count and to speed up the game.

Advancing the count in this case serves to add drama and keeps the batter from engaging in a long series of foul offs with no consequence.

There are however 3 situations in which a foul ball can result in an out. with 2 strikes any foul bunt attempt will result in a strikeout.

with 2 strikes any foul tip that is caught by the catcher will result in a strikeout.

in any count a ball that is fouled and caught by a fielder is a foul out.

Basically the rule exists to foster more and better competition in the sport.

Sorry, I don't have a reference for this, but we studied this in Game Theory: statistically matching the outcome of equal opponents.

When you match any two opponents of absolutely equal skill, the contest should end a stalemate (i.e. the rules should not give advantage to one over the other).

In baseball, if a hypothetically "perfect" pitcher could throw every pitch at the outside corner of the strike zone, it is very difficult to hit the ball in play.

Even the best batter is at a statistical disadvantage in that perfectly-matched contest.

So, they make it so the batter doesn't have to hit the ball in bounds to keep the engagement in play — they need only make contact with the ball to keep from being called out.

That "good enough to try again" rule keeps the competition in better balance without inadvertently giving advantage of one player over the other because of an unbalanced rule.

The MLB's Official Baseball Rules states in Rule 10.15: 10.15 STRIKEOUTS

A strikeout is a statistic credited to a pitcher and charged to a batter when the umpire calls three strikes on a batter, as set forth in this Rule 10.15.

(a)

The official scorer shall score a strikeout whenever a batter: is put out by a third strike caught by the catcher; is put out by a third strike not caught when there is a runner on first before two are out; becomes a runner because a third strike is not caught; or bunts foul on third strike, unless such bunt on third strike results in a foul fly caught by any fielder, in which case the official scorer shall not score a strikeout and shall credit the fielder who catches such foul fly with a putout.

In general, on any given at-bat the pitcher already has an advantage over hitters - on average a batter succeeds less than 40% of the time at the major league level.

As wax eagle notes, this rule gives the batter small advantage to stay alive.

A foul ball is an intermediate result between a "strike" (a total miss) and a "fair ball" (one that goes into play).

Logically, a foul ball should be scored in an intermediate fashion between a strike and a fair ball as well.

One way of doing this is to count "half" strikes for a foul ball.

That would cause a certain amount of game confusion keeping track of these "half" strikes.

Another way of achieving a comparable, and equitable, result is to award the first two foul balls in an at bat as strikes to the pitcher, and the remaining ones as "free" shots to the batter.

In practice, it would mean that about half the foul balls are counted as strikes, and about half (after the second one) are not.

In theory, it means the that "burden of proof" is on the hitter to put the ball in play on the first two fouls, but for the third strike, the "burden of proof" is on the pitcher to get a "full" (not a foul, or "half") strike.

It's not unfair for the pitcher to have foul balls recorded as strikes, while the batter is not put out.

All contacted balls (plus called strikes) are strikes for the pitcher.

That includes "fair balls" that become hits, or outs, as well as foul balls, whether or not they become "strikes" for the batter.

The reason this rule exists is because in the early days of baseball, players would intentionally bunt foul to wear the opposing pitcher down.

A classic example of this is "King" Kelly of the Chicago White Stockings (precursor to our modern day Cubs).

King Kelly was notorious for bunting foul in order to wear down a pitcher and eventually get balls leading to a walk.

Back in those days, foul balls were not strikes.

The rules of baseball had to be changed because of this strategy.

For more information on King Kelly, read: https://en.wikipedia.org/wiki/King_Kelly

Question: From the  Wikipedia entry for foul ball   A strike is issued for the batter if he had fewer than two strikes ...A strike is, however, recorded for the pitcher for every foul ball thebatter hits, regardless of the count.   Why isn´t the batter struck out if he hits a foul ball while he already has two strikes? Why is this situation different than if he has zero or one strikes?

Why does a foul ball not count as a third strike?

Basically the rule exists to foster more and better competition in the sport. in the early days of baseball, players would intentionally bunt foul to wear the opposing pitcher down. Advancing the count in this case serves to add drama and keeps the batter from engaging in a long series of foul offs with no consequence.

This practice aims at engaging the ball more and adding drama and interest to the game. From a technical standpoint, a foul ball is not counted as a third strike as a means of giving the batter an advantage against the pitcher, who knows where the ball is headed, and preventing fouls. This practice fosters fair play and healthy competition. This statically balances the chances of two equal opponents in unequal positions.


The fielding captain decides from which end he wants to start the match and informs the batsmen who then decides who will face the first ball.

Usually this is decided by the preference of the bowler who is going to bowl the first over.

There is nothing in the laws to govern this point.

Most competitions have local rules to cover points where the laws aren't always clear (e.g. number of overs, time limits and so on).

So they might wish to define the starting end (or - by induction - the finishing end of a limited overs game): if so, those responsible for the rules of that competition may wish to prescribe.

(Note that in most indoor versions of the game, playing in moderately large gymnasia, all the bowling is done from one end, with the batsmen changing ends at the completion of each over).

Certainly in practice the fielding captain will nominate his bowler.

Regular bowlers familiar with a ground will usually have a preferred end from which they wish to deliver, and it would be wrong for the laws to override the captain's wishes without good reason.

Similarly some batting openers like to take the first ball and will switch over if the senior man has a preference.

Certainly the laws are silent on what should happen in a dispute.

Suppose the fielding captain wants Bowler A to bowl the first ball to Batsman Z, but batsman Y wants to face him.

Law 42.2 states that the umpires are sole judges of fair and unfair play, so they would intervene if they felt that either side was trying to manipulate a particular striker to face (or not face) the first ball.

Reading between the lines of the law, the batsmen's wishes will have precedence, because if they have selected ends, the fielding side would be guilty of time wasting if they then decided to change the identity of the bowler (see Laws 42.9 fielding side & 42.10 - batsmen wasting time) or the end from which he bowled.

In such a situation most umpires would tell the fielding captain to get on with it.

The batsmen have the thinner end of this particular wedge, because the fielding captain can always switch his bowling around in a manner which he decides will best irritate and perplex them.

In practice the one of the opening pair who plans on taking the first ball will check with the umpires/fielding captain who is bowling and from which end; a refusal to disclose is pretty much unheard of.

I am by no means a cricket expert, but this page seems to suggest that the bowler determines the bowling end based on his technique, preference and variations of an individual pitch.

Depending upon the variations in pitch the bowler chooses his end.

Since the team who bowls first is determined by the captain who wins the coin toss , it seems that there could conceivably be a considerable a strategic advantage to winning the coin toss, choosing to bat second and allowing your bowler to choose his end.

There are no set rules on this.

This is how it happens in the real world.

Fielding captain obviously decides which two bowlers start the proceedings.

He then chats with the two bowlers and asks them their preference.

The senior bowler or the bowler who starts first (in some cases) will get their choice first.

There is rarely a conflict as usually bowlers are able to compromise quickly if there is a disagreement.

The fielding captain or the bowler who balls the 1st over of the match decides it.

The factor mostly considered are wind direction.

The umpires do not explicitly say anything about the end which the game play starts.

There is no rule also based about it.

Maybe the people who wrote the rule book might have thought this as a Minor part of the Game.

Quoting Bill Frindall, aka the Bearded Wonder from this BBC article .

At the start of each innings of a match the fielding captain decides from which end play will begin.

He usually makes this choice in collaboration with his opening bowlers.

When they have decided their individual preference of ends, the captain then decides which bowler he wants to open with and that will determine his choice of end.

So, preference of opening bowlers will help the fielding captain determine from which end play will begin.

It is decided by fielding side captain and the bowler himself.

Few key points which come into the consideration while a bowler chooses an end are:-

The flow of wind:- which helps a swing bowler.

He chooses whether he wants to bowl with the wind or against it.

Both helps in the movement of the ball a lot.

Longest side of the field:-

normally we see this when a spinner starts the attack.

The fielding side captain usually opt for longest side boundary to be on the leg side of a right-handed batsman.

Amount of grass on the pitch:-

Sometimes, the grass covering on a pitch varies from one end to another.

In this case, the fast-bowler chooses the end with grass covering to begin the attack(I am considering that the best bowler of the team will ball the first over).

Superstition:- Few bowlers are there who are superstitious, they choose an end which is away from pavilion or some any other mark.

more form icc world cup :-

Question: In cricket, how is it decided from which end to start the match? Is this a per-ground convention, a decision of the umpires, or either of the captains? Is each innings necessarily started from the same end?

In cricket, how is it decided from which end to start the match?

At the start of each innings of a match the fielding captain decides from which end play will begin.  He usually makes this choice in collaboration with his opening bowlers. The senior bowler or the bowler who starts first (in some cases) will get their choice first.

The decision from which end to start the match usually lies wit the fielding captain, who usually confers with the first or most senior bowler on the matter. There are no specific regulations on this issue, even for disputes, which however are rare. Local rules may apply. One of the parameters considered is the direction of the wind. Less relevant factors include the longest field side, the amount of grass or superstitions.


Chris McDougal , author of Born to Run, a book that will make you want to go run immediately and properly, “Imagine your kid is running into the street and you have to sprint after her in bare feet.

You’d automatically lock into perfect form —

you’d be up on your forefeet, with your back erect, head steady, arms high, elbows driving, and feet touching down quickly on the forefoot and kicking back toward your butt.”

And further, I hope this article will give lots of knowledge about running properly .

First of all congratulations with your milestone!

It feels great to be running.

If you have 6 months of running in your legs now, you probably don't have the worst technique, because then you would have been injured already :=)

If you haven't done so much running in your life before, and never played any sports like football, I think I would have focused on other things before landing on your forefoot.

Focus rather on landing your feet at the center of your gravity and running relaxed with a slightly lean-forward angle.

(Over focusing on forefeet landing almost killed my legs)

Here is a good video of a guy who improves his technique.

The most important thing is that you don't skip your running exercises, regardless of technique!

People often forget that running correctly, is actually quite hard.

Most people that ran a lot during childhood, get it more or less right, but if your the type that never really has run a lot, some instruction can be very helpful.

Internet guides, articles and so on, are good, but I would probably look to your local atletic club where they have competition +800 meter runners and get some lessons there.

You don't have to join the club, but get 3-4 lessons, come back in some months and get some follow-up lessons.

A very good video that explains in detail a good posture in running:

http://www.youtube.com/watch?v=Tx6x2cD6Y8Q .

I used it myself to improve my technique.

You'll find in there all the key elements.

Of course, if you go for trail running, things complicate a little bit.

Responding to several of the answers here: running barefoot may be a fad - and may even work for some minority of the population - but one should be careful and informed if inclined to attempt it.

Careful studies have shown downsides to running barefoot in terms of sacrificing speed/performance and distribution of stress on the foot.

An alternative may be to wear rather minimalistic shoes.

How minimalistic you may go would be very specific to you/your feet.

Consider that having slightly more weight but having the support you really need will go a long way towards avoiding injuries.

As far as your form: it would make sense to be evaluated by a running coach.

They can give you tips on areas you might be able to tweak.

Question: I have about 6 months running regularly, about 1–2 times per week. Today I ran 14 km (about 8 miles) — a milestone for me!  I feel great and I don't want to stop, but I don't know if I'm doing properly or not.  I don't want to get injured or something just for not asking.   How can I tell if my running technique is correct?

How can I tell if I'm running properly

S2: Internet guides, articles and so on, are good, but it is probably a good idea to look to your local atletic club where they have competition +800 meter runners and get some lessons there. When running, it is good to focus rather on landing your feet at the center of your gravity and running relaxed with a slightly lean-forward angle. However, the most important thing is not skipping your running exercises, regardless of technique!

Landing at your center of gravity and adopting a forward angle while running are key to improving your technique. However, regular practice is perhaps more important than form. You are advised to take some running lessons, possibly at a local club.

Regular practice is perhaps more important than form.


Yes, it is LEGAL to switch racket "handed-ness" during play.

From the USTA web site : Q. I am a left-handed tennis player.

During play, I have found that I can hit the tennis ball almost as well with my right hand as I do with my left.

Do USTA rules forbid players to switch hands during play?

A.

No.

You can play with either hand.

In fact, three-time USTA national champion Marty Devlin of Trenton, NJ has employed this “two forehands” style since he started playing tennis.

The old joke when people were preparing to play Marty was to hit to his backhand.

But, alas, he has no backhand.

Also, I have cousins in the Miami area who have played tennis with Jai alai players who will switch handed-ness frequently even during the same point / rally.

I know that in tennis you are allowed to use either hand to hit the ball with the racquet during any point, set or match.

You may not use more than one racquet during any single point, though (though you are allowed to switch racquets between points).

And racquet throwing (for the purpose of hitting the ball) is not allowed - the racquet must be in your hand at the point of contact or you lose the point.

It is perfectly legal though, between shots, to drop the racquet and pick it back up and continue the point.

In tennis, rule #24, which covers all the scenarios in which a player loses a point, does not forbid a player from switching the hand that holds the racket.

PLAYER LOSES POINT

The point is lost if: a. The player serves two consecutive faults; or b. The player does not return the ball in play before it bounces twice consecutively; or c.

The player returns the ball in play so that it hits the ground, or before it bounces, an object, outside the correct court; or d.

The player returns the ball in play so that, before it bounces, it hits a permanentfixture; or

e. The receiver returns the ser vice before it bounces; or f.

The player deliberately carries or catches the ball in play on the racket or deliberately touches it with the racket more than once; or g. The player or the racket, whether in the player’s hand or not, or anythingwhich the player is wearing or carrying touches the net, net posts/singlessticks, cord or metal cable, strap or band, or the opponent’s court at any timewhile the ball is in play; or h. The player hits the ball before it has passed the net; or i.

The ball in play touches the player or anything that the player is wearing orcarrying, except the racket; or j.

The ball in play touches the racket when the player is not holding it; or k. The player deliberately and materially changes the shape of the racket whenthe ball is in play; or

l. In doubles, both players touch the ball when returning it.

To address your second question: Rule #24.j.

states if the ball in play touches the racket when the player is not holding it, the player loses the point.

USTA Regulations IV.D. Table 17 provides an official with guidelines on when to assess a penalty for racket abuse.

The guidelines state an official should always penalize throwing a racket that, even inadvertently, strikes a person.

The guidelines state an official should generally penalize: Throwing a racket into the fence or net

Throwing a racket in anger or in any manner that could or does endanger any person or that damages any part of the court surface or equipment Breaking a racket

The guidelines state an official should sometimes penalize: Tossing a racket into the air

Tossing a racket at the player’s bag Bouncing a racket on the court

The complete Friend at Court can be read here.

It is perfectly legal in table tennis to change the racket to other hand during a point.

Though uncommon and extremely difficult, it does provide a few exciting moments for the spectators.

ITTF has compiled a video capturing these exciting moments.

And if it is legal for a point, it should be legal for a set and a match as well.

Regarding squash, it is perfectly alright to switch your hands while playing a shot.

You can use both your hands too.

Here is a video which shows that it is allowed.

Question: Can you hit with different hands during the same  point? set? match?  Also, is racket throwing authorised?

Is it legal in racket sports to pass the racket from one hand to the other?

it is LEGAL to switch racket "handed-ness" during play. In tennis, rule #24, which covers all the scenarios in which a player loses a point, does not forbid a player from switching the hand that holds the racket. Moreover, it is perfectly legal in table tennis to change the racket to other hand during a point.  Furthermore, in squash, it is perfectly alright to switch your hands while playing a shot.

In tennis it is allowed to pass the racket from one hand to the other, as well as to use either hand. Switching hands when holding a racket is also allowed in squash.

Switching hands when holding a racket is allowed in squash.


How much are you kicking?

Try holding a flutterboard/kickboard/buoy between your legs and continuing the arm motion of front crawl.

This does two things.

Removes the leg muscles from the equation Keeps your legs up, which makes swimming MUCH easier.

The main trick in efficient swimming is to learn to swim downhill.

You want to 'Press the Buoy' which is push your chest (full of air) down, and use it as leverage to get your legs higher.

You sort of eventually end up swimming downhill a bit.

Another trick is to tuck your chin into your chest, imagining you are pulling your neck and spine far enough to tug your legs up.

(Its just a trick to teach you to lean forward and press the buoy, but the image works).

If you try to feel yourself pulling your legs up by your chin it can be effective.

Basically these are approaches to being more efficient.

This might seem a stupid question, but are you breathing out when your head is underwater?

Most swimmers that I see struggling to catch their breath are holding their breath when their head is in the water, and then trying to both breathe out and in when they turn their head above water.

There's not enough time to do both in crawl and they inevitably struggle to catch their breath, as you've got to breathe out before you can breathe in.

A good bet is that this is probably caused by being nervous, and you might be hyperventilating.

Given your fitness level, there's probably not a physical reason for getting out of breath - and I bet your breath very quickly returns to normal when you grab the side of the pool.

The good news is that this is 100% fixable - and you've already taken a big step: recognizing that there is a problem.

Time in the water, and maybe some coaching will quickly bring up your experience level, and your confidence, which should smooth out those nerves.

When I started swimming seriously, about 4 years ago, I struggled with exactly the same problem .

It took me a long time to break the 100m barrier for front crawl , doing bi-lateral breathing.

Uni-lateral breathing was a little better

but I still struggled with a sensation of panic and being out of breath.

Once I had broken the 100m limit, suddenly it became possible to go much farther, as if there is a transition between how I would breath normally on land and how I needed to breath whilst swimming.

I still feel a slight pinch during training warm-up at this point, as if my lungs 'change gear'.

To beat the limit

I : slowed my swimming to a very gentle pace so as to be as relaxed as possible repeated 50m swims at first, with a break between each to recover, then 100m swims with a break eventually

, I felt I could attempt to go past the 100m and try for 150m Once I was getting to 150m, I very quickly made it to 200, 300 etc.

One of the key things that helped me was to beat the barrier

was expelling 50% of each breath immediately after inhaling, ie.

as my face re-entered the water, I already started to breath out.

The remainder of the air I slowly breathed out, through nose and mouth simultaneously, during the time my face remained under water, such that after 3 strokes it was all gone and ready for the next inhale.

As others have indicated here, breathing out is very important; when swimming you should be either breathing in or out but not holding your breath.

My coach explained the panicy feeling you get as being the need to expel the C0-2 from your lungs following breathing in, which is not something you'd instinctively think to do.

I'm in a similar situation, albeit I only run half-marathons and bike up to 60km.

When I started swimming I had the exact same problem, that I couldn't breathe according to what felt a good swim effort.

In the end I relaxed my swim speed as well as allowed my self to breathe every time I pulled back with an arm.

I really focused on my breath and feeling good in the water.

Everything else was secondary to being able to breathe calmly.

I train in a group, and before I would have to take a break every 50m and wait till my breathing came from a frantic gasping to a relaxed in-/exhale as while running.

After the change I swam slower, but could actually manage 1h30 of training, where previously I would be at the end of my strength after 30min.

Now, a few months later I can keep up with my group, and I breathe every 2 arm pulls, sometimes every 3 to switch breathing sides.

Question: I am now starting to learn how to swim and have found that I have trouble swimming with my head in the water. Although I breathe every 1 or 2 strokes (front crawl) I found that my heart rate rises pretty high and soon I found myself gasping for air.  I am not out of shape; I run marathons and do long MTB races (80km) so I thought I can control my breathing during effort, but this seems a different kind of challenge.

Why do I get out of breath so quickly when swimming?

Relaxing in the water seems to be the key to improving breathing when swimming. Techniques that may help include spending more time in the water, slowing the swimming speed until you get the breathing right and using flutterboards to help perfect the arm stroke and breathing technique.

There are a number of techniques to increase your tolerance. You could try swimming with your hands only, practice downhill swimming, increase your pace gradually and experiment with swimming positions. Part of the problem might be psychological. Familiarizing yourself with the water, and staying calm and confident are critical to your improvement. Moreover, breathing in and out constantly and evenly is key to swimming. You should practice your breathing rhythm and avoid holding your breath.

Breathing in and out constantly and evenly is key to swimming. You should practice your breathing rhythm and avoid holding your breath.


Actually, most swimmers at this level of competition wear two caps.

Dana Vollmer, who won gold with a new world-record time in the 100m butterfly, actually lost her outer cap in the pool on the return leg of that event.

Thus, the first reason; redundancy.

These caps are latex rubber, which doesn't mix well with chlorine and will eventually degrade, and as Dana's swim shows, even a brand-new cap can slip right off.

If the swimmer, especially a female swimmer, had only one cap, losing it and releasing their hair would drastically increase the drag they have to swim against in the water.

Second, as Rory states, a common (though not universal) way to put all your headgear on is to put one swim cap on, then put your goggles on, then cover the goggle strap with another swim cap.

Not only does it reduce drag on the goggle strap (which is minor), it helps keep your goggles in one place (MUCH more important).

I was on a swim team when I was much younger, and I lost count of how many times the shock of entering the water ripped my goggles right off my eyes.

You still have to swim if it happens, but it becomes a HUGE distraction that can take you right out of the race.

At your average junior swim meet, losing a race to your goggles is embarassing but not devastating.

At the Olympics, it would be a heartbreaker.

The two caps are also made of different materials.

The inner cap is latex, which stays on the head better, but wrinkles.

The outer cap is silicone, better for reducing drag.

"The outer silicone cap better maintains the shape and does not wrinkle as much, thereby causing less drag," Salo told Yahoo!

Sports.

- Why do Olympic-level swimmers wear two caps?

It is for speed- if you have your goggles on over your cap

it upsets water flow, so the second cap over that holds the goggles safely on and streamlines the head.

Sure, it's an infinitesimally small benefit, but at that level it is important.

Additionally, some sports manufacturers make some specifically to be worn like this to reduce drag further.

It helps them swim faster.

it not for hair.

Its help b/c

the water will just flow over the cap.

I know because we are talking about it in science

he wore two caps only because if one comes off he has a back up already on and it supports the goggles making them stay in their lace under the second cap as the goggles may come off from diving.

Question: Just now I saw Michael Phelps competing in the 400m Medley heats (London Olympics 2012). After he finished the race, I saw him take off two caps. I can imagine that a swimmer uses one, but what is the reason for wearing two caps?   Is this something new? Does it help him swim faster?

Why do Michael Phelps and some other swimmers wear two caps?

Swimmers wear two caps to reduce drag, hold their goggles in place and ensure their hair is not released if a cap is lost. The second cap is made of a more aerodynamic material. The second cap also holds the goggles in place and the two caps ensure the hair is not released as loose hair, especially if long, creates a lot of drag.

A reason to wear two caps is to have a back-up in case the first one comes off. In competitive swimming, released hair is a serious disadvantage. A second cap is also a means of supporting and securing your goggles in place. Some argue that the caps are designed specifically to reduce drag and increase swimming speed. To this end, one is made out of latex and one out of silicone.

A second cap is a means of supporting and securing your goggles in place.

The caps are designed specifically to reduce drag and increase swimming speed. To this end, one is made out of latex and one out of silicone.


Endomondo.com works very well importing all the information from Nike+.

After that you can use it to export individually to some other services, or use it as I think is pretty good.

Update:

Sorry folks for taking so long to get around to this update

- I had to retire this tool in 2016 ago due to nike changing their API, and not having enough time to re-engineer the code, so this is no longer an acceptable solution.

Original Post:

I wrote a tool to help export workouts from nike+ for upload into other tools like Strava or Runkeeper: http://nikeplusexporter.rhysmccaig.com/

Trailrunnerx on osx can sync with nike+, including after Nike's recent changes to their API.

From there one can export to various file formats.

The gpx-tracks has worked for me for uploading to Strava and MapMyRun.

Runkeeper on the other hand seemed to have trouble extracting the relevant data from these files.

The Smashrun website can sync with nike+ directly.

It's good for numbers, but doesn't have maps yet.

MayMyRun also connects directly to Nike+, but doesn't seem to import gps data/maps and doesn't offer any graphs or statistics.

It does so only when importing from files rather than through nike+.

Note that I've changed this answer several times, to keep up with current status.

TLDR:

Use Smashrun , then Tapiriik

In the previous months/years Nike has been changing the way it provides data; including who it provides it to.

I'd been using the exporter by Rhys McCaig for quite some time, but he has since discontinued his tool.

I've also tried Tapiriik , which is great, but the Nike+ service is still in beta

(I always get the message "Some activities could not be synchronized").

Smashrun is able to import Nike+ runs directly.

From there if you still want to export somewhere else (or just upload TCX files to Dropbox)

you can use Tapiriik .

http://www.rungap.com/ supports a whole bunch of apps including Runkeeper, Garmin and Nike+.

Unfortunately, it's doesn't provide online access.

Just smartphone app access.

Update: Smashrun can import runs from Nike+ and Garmin directly.

It also supports importing gpx/tcx files.

I have the free membership for now.

It is pretty bare bones, but from the looks of it the pro membership provides more valuable information and analytics.

The Android app

SyncMyTracks can import and export from and to Nike+, Strava, RunKeeper, Endomondo, Garmin Connect and other services.

I've been using it for a few months, and it works great!

I'm not sure what format the Nike files are, but the Fit File Repair Tool offers the most comprehensive options for conversion from and into the most commonly used formats (fit, tcx, and hrm).

On top of that, it lets you fix faulty files, e.g. when the gps or the heart rate monitor went crazy due to interferences.

If conversion to tcx is sufficient, I found tcx creator to work quite smoothely.

It's main purpose is to combine hrm files (from your heart rate monitor) with gpx files (from your gps device),

but it also works if you skip the gpx files and just feed it with hrm.

So basically, what you need to do is check what file format Nike produced for you and check what your new online service can import (most likely one or more of the above).

According to the tcx creator website, all of the following accept tcx files: endomondo.com, strava.com, connect.garmin.com, runkeeper.com

The (free) online app called Tapiriik provides a great way to sync between many applications.

Including endomondo, strave, runkeeper, dropbox, garmin, ride with gps, motivato, and many others.

I have written as well a PHP script to export those data: https://github.com/cheesemacfly/nikeplusexport

(there is a link to a demo on the page)

The main difference I have with the other ones is that the time for each waypoint is calculated so I found it more precise.

It works only with the runs having GPS data and can export to GPX, TCX and JSON.

If you have an iOS device, you might find this app handy: https://rungap.zendesk.com/entries/45048583-Using-Endomondo-with-RunGap

Question: I'm disillusioned with Nike+, where I've been logging runs for over a year, and ready to try something new (in this case, Strava). How can I export my data from Nike+ so I'm not losing it all?

What is the simplest way to transfer data between online running logs?

There are a number of programs that ca be used to synch data between Nike+ and Strava. These include SmashRun, SyncMyTracks and Trapiriik, among others.

There is a good number of available applications and websites that either sync with or import data from Nike+. These include Endomondo, railrunnerx, gpx-tracks, Smashrun, MayMyRun, Tapiriik and SyncMyTracks. Another option would be to use a file repair software, such as the Fit File Repair Tool, to convert your data into the desired format.


I have heard of six being scored in extra time in the FA Cup fixture Leyton Orient v Droylesden, Orient scoring all six in winning 8 - 2.This

took place on 7 December 2010.

There is a match report on the BBC: BBC NEWS

Arsenal and reading 4 goals in overtime isn't a new record.

Most goals scored in extra time in FIFA World cup

was 5 goals in the match between Italy vs West Germany on 1970.

Youtube

I couldn't find any match with more than 5 goals scored in extra time..

Late reply, but I found a match with 7 goals in extra time: DFB Pokal (German Cup) , 1974-10-26, between Viktoria Köln and TSG Usingen - from 0-0 to 6-1 ( link , link ).

I saw a thread in Tony's Nonleague Matters forum mentioning two more matches with 6 goals in extra time: 2006 Welsh Cup between Queens Park and Brymbo - from 2-2 to 3-7 ( link ) 1995 FA Cup tie between Walsall and Torquay - from 3-3 to 8-4 ( link )

In Coupe Gambardella ( U19 Men's French cup ); [round of 64 and round of 32] 12 goals in extra time: Douai SC-Amiens SC: 0-0 to 0-12 Coupe Gambardella 1998-99 10 goals in extra time: Besançon RC-Olympique Lyon: 0-0 to 0-10 Coupe Gambardella 1996-97 In Coupe des Dames 2017-18 ( Luxembourg Women's cup ) [round of 32] 11 goals in extra time: Union Mertert Wasserbillig-Aspelt Remich Bous Entente: 1-1 to 7-6 Soccerway In UEFA Women's Champions League 2017-18 [Final] 5 goals in extra time: VFL Wolfsburg-Olympique Lyon: 0-0 to 1-4 UEFA

I also saw a match with 7 goals in overtime in the Coupe de France (French Cup) in round of 512

but I can not find the match in question.

In German Central Rhine Regional Cup 2020 [quarter-finals] 6 goals in extra time: Germania Windeck - Viktoria Arnoldsweiler 0:0

to 0:6 kicker

Question: On 30-Oct-2012,  Arsenal defeated Reading  with an incredible score of 7-5. A more astonishing fact is that 4 goals were scored in Extra-time.  Is this the record for the most number of goals in extra-time, in a single game? If not, which match holds the record?

Most number of extra-time Goals

From the evidence, it appears that 12 is the highest number of goals scored in extra time. That was in  the Coupe Gambardella  ( U19 Men's French cup ); [round of 64 and round of 32]  12 goals  in extra time: Douai SC-Amiens SC: 0-0 to  0-12.

There are conflicting views on the maximum number of extra-time goals. Answers vary from 6 to 12, where France holds the record.


You are right that the French Open is the only Grand Slam tournament without Hawkeye,

The reason is that Clay, unlike grass and hardcourts, leaves a mark that players and umpires can check and verify if the ball was in or out.

You can argue that some mistakes can be made but that's quite rare, A hawkeye system is very expensive and the cost/benefit ratio doesn't pays.

Gilbert Ysern, the director general of the French Open and a former umpire, address to this:

“I don't think we need it,” he said in an interview in his office.

“There are ball marks on clay,” Ysern said with a genial smile, “and our chair umpires are used to checking the marks when needed, and, so why would we need Hawk-Eye?”

And the disputes?

“It happens very, very rarely that the officials can't find the mark,” he said.

Source

I strongly suspect that the manufacturers of Hawkeye and similar ball tracking systems would actually prefer not to have a hard 'ground truth' to compare to being beamed live to millions of viewers.

These systems are not as accurate as the TV graphics imply and there use as part of the umpiring process is not all to do with accuracy.

It is as much about having a non-human, dispassionate system

have the final say when the humans can't agree as arguing with a machine is futile.

The manufacturers of Hawkeye claim a mean accuracy of 3.6mm, although this figure, or at least its interpretation has been called into question .

Basically, since this is an average over some range of shots, it is likely that the actual error in certain circumstances is significantly higher (as detailed in the second reference).

Errors approaching 10mm could easily turn the correct result, as observed by the skid mark on clay ground truth, into an incorrect Hawkeye call.

It would be terrible publicity to have a top player angrily pointing to the clear evidence on the court that differs from the Hawkeye prediction.

Clay courts leave a visible mark which shows where the ball lands.

This is the reason why the staff at Roland Garros clear the court often during a match so there wont be overlap of marks(or mistake of the actual mark), which can cause confusion.

If a ball is questionable, then the referee will come down and check the mark on the court and make his decision about whether it was in or out .

Balls can skid much longer distances on clay.

On hard courts only the ball measurably changes (deforms) on impact.

On clay both the ball and the court are changing simultaneously as a layer of dirt is shifted around.

These factors make Hawk-Eye's job more challenging on clay and it would be logical to conclude that Hawk-Eye's margin of error increases on clay.

Hawk Eye is in general more accurate than the human eye

but that doesn't mean it's 100% perfect.

It will always remain an approximation of the "ground truth".

With clay courts we have the unique ability to see the actual physical mark.

This hard, physical evidence should be always preferred to approximation, no matter how accurate.

Question: I have never seen Hawk-Eye technology to be used on clay tournaments. French Open is running at the moment and it is not being used there.  What are the reasons for not using this technology on clay? Do tennis federations have some rules against it?

Why is Hawk-Eye not used on clay courts

The reason is that Clay, unlike grass and hardcourts, leaves a mark that players and umpires can check and verify if the ball was in or out. There is always a margin of error with technology and it would be embarrassing for the manufacturers if the technology called differently from the actual evidence in the clay.

Unlike grass, clay leaves a visible mark. Mistakes are rare, therefore the cost of a hawkeye system is not justified. You might also want to consider that the Hawkeye system is only an approximation of hard evidence. Since clay leaves a visible trace, Hawkeye is not as effective, and therefore redundant. More to the point, some people argue that ball tracking systems like Hawkeye are not actually objective, so possible clash with visible evidence, such as clay, may cause bad publicity. Finally, the Hawkeye system is not as effective on clay, given that balls go further and may deform on impact, while court conditions might change.

Some people argue that ball tracking systems like Hawkeye are not actually objective, so possible clash with visible evidence, such as clay, may cause bad publicity.

The Hawkeye system is not as effective on clay, given that balls go further and may deform on impact, while court conditions might change.

You might want to consider that the Hawkeye system is only an approximation of hard evidence. Since clay leaves a visible trace, Hawkeye is not as effective, and therefore redundant.


In addition to the previous answer a couple of other interesting examples spring to mind.

These from Test matches: The first abandoned test I can find was West Indies vs England , Sabina Park (1998).

The match was called off after only 10 overs due to an unplayable pitch (Scorecard) .

A similar occurrence in Antigua in 2009, where the game was called off after 10 deliveries.

(Cricinfo report) .

This was due to the sandy condition of the recently relaid outfield being deemed dangerous to bowlers.

The second Test between England and West Indies at the Sir Vivian Richards stadium in Antigua has been abandoned after just ten deliveries, after the sand-based outfield was deemed a safety risk to the bowlers.

The test between England and Pakistan at the Oval in 2006 was abandoned when the Pakistan team refused to emerge from their dressing room after tea on the 4th day, feeling they had been unfairly docked 5 runs for ball-tampering.

(Scorecard)

The match was eventually awarded to England.

The first semi final match between India and Sri Lanka in world cup 1996 was stopped due to disturbance in the crowd.

Read the note of the match: At the fall of the 8th Indian wicket, sections of the crowd vented their disgust with the state of the match by setting fire to some areas of the stands and throwing fruit and waterbottles onto the field.

The match was briefly stopped and when play was about to resume, the crowd again threw bottles at the deep fielders.

The match referee stopped the game and the game was awarded to Sri Lanka by default.

I don't know any other match which was stopped due to such reasons.

Along with the other examples already cited, an unusual incident occurred in 1975, when the 3rd Ashes Test at Headingley was abandoned as a draw due to an act of sabotage : before the fifth day's play, the pitch was dug up and damaged with oil by campaigners calling for the release of a convicted criminal.

The India vs West Indies game in Rajkot,2002 was stopped amidst security threats after chuckers started attacking players with water bottles and sandbags.

India won by 81 runs by virtue of D/L method.

Relevant CricInfo article.

The India vs Sri Lanka game in Feroz Shah Kotla, Delhi, 2009 due to dangerous pitch conditions.

The series had already been won by India and the two captains agreed to a draw.

Kotla Pitch Fiasco

An instance where a Test match was ended by crowd disturbance was the Fifth Test between West Indies and Australia at Sabina Park, Kingston in May 1978.

West Indies were 9 wickets down in their second innings and over 100 runs behind late on the fifth day when parts of the crowd rioted.

Police were called and players retreated to the dressing room, played being called off.

A decision was made that evening by the management of the two teams to complete the Test on the following morning, which would have been the sixth day of the game.

One umpire agreed to stand on the extra day, the other didn't

and so the match did not continue.

The match scorecard is on Cricinfo here .

Peter Toohey played for Australia in that Test, his account of the incident is here .

In a match at Sialkot(India's tour of Pakistan 1984-85), Pakistan had put India in to bat after winning the toss.

India was cruising at 210/3 after 40 overs with Dilip Vengsarkar well-set on 94*.

The match was then abandoned following news of the assasination of India's Prime Minister Indira Gandhi.

Match scorecard is here .

The sad addition to the examples above are all the Sheffield Shield matches in progress on 25 November 2014 .

Play in the New South Wales vs South Australia match was abandoned for the day when Phillip Hughes was critically injured by a bouncer; all the other in progress matches were abandoned at the end of the day's play.

In addition to all of the other answers, the second Test between Pakistan and Sri Lanka in 2008-09 was abandoned on 3 March 2009, after the Sri Lankan cricket team was attacked on its way to the cricket ground.

Since then, the only international matches played in Pakistan have been those played on Zimbabwe's tour of the country in 2015.

Question: A cricket match can be stopped due to weather conditions (rain) or bad light before getting the result.  Have any international matches been stopped before getting the result for any reasons besides weather or bad lighting in cricket history?

Have any cricket matches been stopped for reasons other than weather/lighting?

Cricket matches have been stopped for a number of reasons not related to weather. Unplayable pitch has stopped many matches. Crticial injury to a player, when a player was injured by a bouncer in Australia. In the test match between England and Pakistan in 2006, the Pakistan team refused to come out of the dressing room after tea as they felt they had been wrongly accused and penalised for ball tampering.

A good number of cricket matches has been stopped due to dangerous pitch conditions, players' sit down and players' injury. Problems are not exclusive to the organization or the players. There are examples of crowd disturbances, political unrest and criminal activity that led to a game's suspension.


So I would like to know if there is some sports for which the fact to be smaller than his adversary can be a distinct advantage?

Yes they do exist.

But here's one example:

In horse racing, having a smaller and lighter rider is more advantageous.

It lets the horse sprint faster because there's less weight on its back.

Source: taken of wikipedia

Gymnasts are also usually quite small, there is actually some debate over whether gymnastics can affect growth (but I don't think there is much evidence behind this).

According to this website American gold medalist Gabrielle Douglas is four feet, eleven inches, and 90 pounds .

http://www.boston.com/sports/blogs/statsdriven/2012/08/the_bodies_of_champion_gymnast.html Also height isn't always an advantage in soccer, just look at the average height of the Barcelona team (Messi, Xavi, Iniesta, Pedro etc).

In cricket being short may not help you in selection in the team.

But if a player is a batsman, he may get some advantages in batting.

(or disadvantages for tall players do not apply)

Tall players have to bend more than short players while batting.

Bowlers have to bowl under their shoulders otherwise it will considered a No ball (after two bouncers).

So they have to shorten their length.

They can play yorker length ball better than tall players because normally short players have high backlift and tall players have to keep the bat lower while playing the shot.

However, if you are a bowler (specially fast bowler), being a taller is an advantage.

I can think of a couple instances where it is an advantage for the athlete to be small.

They are both "racing" situations, and the athlete in question is a "controller."

The first is the "coxswain" (caller) on a rowing team.

His function is necessary, but the smaller he is, the less burden on his teammates.

The second, as someone else pointed out, is a jockey on a horse, where the jockey has the dual role of controlling the horse and not being a burden on the horse.

In Curling athletes with a low center of gravity (smaller one generally) are helped in the stability of the slip.

The stability of the slip is one of the most important feature to be a strong curler.

During the action of broom is important the hands and back power, while during the slip is important to have muscolar legs, so power and compact athletes have a slight head start

Besides all sports that have been mentioned already, I would like to add shorttrack to that list.

Being short and having little weight gives the rider an advantage to be more agile while fighting for the best positions and taking over other riders.

However, this does not mean that taller riders cannot compete with the best, since they might bring more power.

Ter Mors , for example, is often by far the tallest rider on the ice.

Distance running is another sport where a smaller athlete may have an advantage.

When work = mass * distance, an athlete with smaller mass will do less work to cover the distance.

If two athletes have the same capacity for rate of work - that is, they can do the same amount of work in a given span of time - the lighter one will win a race.

There are limits to this - at some point being lighter limits your capacity to do work -

but in general lighter is better for distance runners.

Shooting From wikipedia : in shooting sports, a shorter shooter can maintain better balance when standing for long periods of time holding a gun, as well as keep their gun steady.

Motorsports, like most other racing sports, typically favors drivers that are lightweight, which gives smaller, lighter drivers an advantage.

While most motorsport organizations feature a minimum chassis weight in the regulations, this often does not take driver weight into consideration.

This allows cars with lighter drivers to have a slight weight advantage against cars with heavier drivers.

This is prevalent in open-wheel racing, particularly karts, where the karts themselves are all but equal in weight, and

the differences mainly come from the driver's weight.

TL;DR,

Regulated car weight + lighter driver allows for faster, more agile movement vs. cars with heavier drivers.

Rock climbing Lead climbing and bouldering nowadays tends to favour smaller / lighter people than taller / heavier.

I know this can end up as a long debate, but for a shorter person looking for a sport this is something to look into!

Question: Many sports put forward tall players. I know that everybody can play any sport, but I've noticed that in professional teams (basketball, volleyball, soccer, tennis, ...) there is a tendency to see tall people. It's maybe due to advantages that high sizing can provide. It's depending of each sport. So I would like to know if there is some sports for which the fact to be smaller than his adversary can be a distinct advantage?

Are there sports in which being smaller than your adversary can be a distinct advantage?

There are a larhe number of sports in which being small is a definite advantage. These include horse racing, gymnastics, rowing, motor racing, shooting, rock climbing and long distance running.

There is a number of sports where a smaller frame is actually a benefit. These include horse racing, gymnastics, cricket, rowing, short track, distance running, shooting, motorsports and different types of climbing. This is often related to balance and less weight, even though certain sports like gymnastics can arguably hinder development.


This Footytube forum discussion mentions several players (most French) from other countries: Zidane (Algeria), Desailly (Ghana), Vieira (Senegal), that went on to not play for their country of birth.

The decision by Algeria to not accept Zidane because he was too slow sure turned out to be a poor decision, 'eh?

One other that comes to mind is Dani Osvaldo , who plays for Italy but was born in Argentina (a common relationship for the two countries).

The aforementioned Kevin-Prince (Germany) plays for Ghana and played against Germany.

Unfortunately, none of these players have scored against their countries of birth as far as I can see scanning their International Goals, but the chances are high that each played against their country of birth (all three French players have many, many caps for Les Bleus)

Players who play against their national team: David Trezeguet (Argentina): at least played a game against Argentine (playing for france).

Guillermo

Franco (Argentina):

Plays for Mexico, and plays at least two times against argentina.

One he didn't enter the field, and the other he enter as a substitute.

The two matches where on world cup (2006 and 2010) Player who didn't play against his national team: Alfredo Di Stefano (Argentina): I can't find any reference if he plays a match vs Argentina when he was playing for Spain.

Camoranesi (Argentina): didn't play against Argentina, when he was playing for Italy.

After looking at this list of players who have switched nationalities in football I saw that Mathias Fernadez represented Chile despite being Argentinian.

In a game in 2011 he scored vs Argentina.

He does however consider himself Chilean having left Argentina aged 4.

Germany's has this tradition of having few players from Austria and Poland(Klose and Podolski).

During the famous Euro 2008 match between Germany and Poland, Lukas Podalski scored both of Germany goals with one of them assisted by fellow striker, Klose.

As a respect for his native country Podalski didn't celebrate the goal and also later told that it was emotional to score against his country.

After looking at this list of players who have switched nationalities in football I saw that Mathias Fernadez represented Chile despite being Argentinian.

In a game in 2011 he scored vs Argentina.

He does however consider himself Chilean having left Argentina aged 4.

There are quite a few actually; practically every game between Turkey and Germany have had some player "upsetting" one side.

Examples: 07.10.2011

Turkish left-back Hakan Balta scored the only goal for Turkey, as the home team lost 3-1.

He's born in W. Berlin .

International friendly game where Turkey won 2-1, goals scored by H.

Altintop and N. Sahin , both born and raised in Germany.

Similarly M. Özil scored against Turkey in multiple games; even though he's not born in Turkey his parents are both Turkish, and he has on several occasions

expressed having a Turkish identity.

If we continue with Germany, more recent players were L. Podolski and M. Klose , who have played against Poland.

The duo scored a goal in Euro 2008 and chose not to celebrate it

( Podi actually scored both goals, Klose assisted one of them).

In the game between Albania and Switzerland in 2011, X. Shaqiri scored the opening goal.

I'm not sure if it counts though, as he's born in Kosovo, but he is ethnically speaking a "Kosovo-Albanian" (not sure if it's called that in English, sorry).

In the end, Switzerland won with two goals to one.

Interestingly, almost all players on the pitch were born in Kosovo or Albania, so it was basically a derby!

Question: Diego Costa is making his debut for Spain tonight and he will almost certainly go to Brazil as their main striker considering his form this year. You could imagine the reception he would get playing over there but if he lined up vs Brazil or even scored against them then I'm not sure he could ever go back!   Does anyone know of any cases where nationalised players have played or even scored against their country of birth?

Nationalised players scoring against their country of birth

A number of footbal players have changed nationality and then played against their previos nationality team. Kevin-Prince (Germany) plays for Ghana and played against Germany.  David Trezeguet  (Argentina) at least played a game against Argentine (playing for France).  In Germany,  L. Podolski  and  M. Klose, originally Polish, have played against Poland.  In the game between Albania and Switzerland in 2011, X. Shaqiri scored the opening goal.

There are several instances of players scoring against their country of birth. Most example pertain to France, Germany and Argentina. However, such players are often raised outside their country of birth.


Absolutely.

Ken Griffey Jr. and Ken Griffey Sr. played together in 1990 for the Seattle Mariners.

They once hit back to back home runs in a game.

They played about a month together (8/31 to the end of the season).

In Hockey, Gordie Howe played with his sons Mark and Marty in 1979-80 for the Hartford Whalers.

Wikipedia has a nice page with a list of familial relations in the NHL (they seem to have more than most leagues, probably because the sport is less popular so more likely for familial relations to be successful).

The direct link to the Howes' is at Legends of Hockey .

In the NFL, it doesn't look like anyone really did in the modern era due to the very short career length compared to other sports (except for kickers); in the 1920s, Ted and Charles Nesser played together, Ted as player-coach, and I don't doubt a few more similar occurrences would be found if you looked through the 10s and 20s.

George Wilson coached his son (also George) for the 1966 Miami Dolphins, the only example of that I found.

Ed and Brad Budde were the closest to playing with each other from the list I saw, Ed playing 1963-1976 for the Chiefs and Brad joining the Chiefs in 1980-1986.

This is from a list of father-son relationships from the Pro Football HOF .

From the comments, Leatherwing noted that Wikipedia also has a good NBA Father/Son page ; Kobe Bryant nearly overlapped with Bean, his father (1992/1996).

I realise it's not father and son, but Paul Elvstrøm sailed with his daughter Trine .

They won the 1983/4 European Tornado Championships, were 4th in the 1984 Los Angeles Olympics, and 15th at the 1988 Seoul Olympics.

In Cricket there are several examples of that:18 times a father and son have played in the same match

In 1851 and 1853

even William Lillywhite has played with his two sons: John and James

In (international) football : Eiður and Arnór Gudjohnsen.

On 24 April 1996 , he and his father entered football history in an Iceland international friendly in Tallinn.

Arnór started the match, and Eiður came on in the second half as a substitute for his father .

I don't know if car racing meets the definition of a sport in the OP's question, but there have been some contemporaneous fathers and sons in car racing.

Perhaps the most famous is Dale Earnhardt Sr.

and

Jr. They were in the same race when Earnhardt Sr. died.

This weekend 55 year old Dave Beasant was included on the bench for Stevenage FC as a second choice goalkeeper, in place of his injured son Sam who is also a Stevenage goalkeeper.

So they will never appear in the same team, or even in the same squad, but are both currently 'active' players for their club.

Also another recent case in football was Brazilian legend Rivaldo playing for the same team as his son, Rivaldinho.

They both played for Brazilian team Mogi Mirim earlier this year.

Italian basketball legend Dino Meneghin played against his 16-year-old son Andrea in 1990, in a game of the top professional Italian league.

He was 40 at the time.

Source: Dino Meneghin, the eternal champion .

In ice hockey, Sami and Kasperi Kapanen played last season in the Finnish league.

It's actually fairly common in U.S. auto racing; teams in those sports are often family owned and passed down between generations.

Lee Petty raced against two of his sons, Richard and Maurice, in the same NASCAR race in 1960.

Mario Andretti raced alongside his son Michael in the CART Indy Car series for 8 years, from Michael's rookie year in 1984 (Mario having rejoined the Indy Car series from Formula-1 in '82), to 1992 when Mario retired for good (becoming Michael's crew chief).

From 1990 to 1992, Mario and Michael were joined on the circuit by Jeff, Mario's son and Michael's brother, who raced in CART until a serious crash in 1994 effectively ended his career.

Michael, in turn, practiced alongside his own son Marco before the latter's first Indy 500 in 2006, but the two never competed in a race as Michael had officially retired in 2002.

Al Unser Sr and Jr were both in the American Championship (aka CART) for 11 years before "Big Al"'s retirement in 1994.

Al Sr and his brother Bobby Unser also raced together.

Dale Earnhardts Jr and Sr competed together in the Winston Cup Series in 2000 and 2001 before Sr's fatal crash at Daytona.

In motorsports, Jan Magnussen is still an active competitive driver in Danish touring cars while his son Kevin drives for McLaren in Formula 1.

This may not count since they are very different series.

Martin Brundle and his son Alex Brundle competed in the same team, Greaves Motorsport, driving at the 24 hours of Le Mans in 2012:

According to this FIFA article also Carlos Alonso and Juan Carlos Balazar play in the same official match in first division Peruvian football league

Gordie Howe came out of retirement to play with his sons, Mark and Marty Howe, when the WHA came into being.

After the WHA merged with the NHL, Mark and Gordie played together with the Hartford Whalers for one season.

Sources: Gordie Howe , Mark Howe

Also in curling is possible to find some matches where father and son play in the same match: On this article from Milwakee Journal (date 27 feb 1937!)

there is the news where in two matches there where fathers and sons: George La Marre played versus his sons William, Edwards and Charles and on another rink Lachman MacDonald played with his son Bruce

On november 2011, according to this article the famous Glenn Howard played versus his son Scott

Conrad Harrison and his son Dean Harrison both won TT titles in the same week.

According to Wikipedia : With his father Conrad Harrison winning the Sidecar Race 1 and Dean Harrison's Lightweight win

this was the first occasion of father/son winners in different classes during the same race week.

Question: Has there ever been a father and son in the NFL/NBA/NHL/MLB who were both active players at the same time?

Father and son who were active players at the same time in NFL/NBA/NHL/MLB?

Ken Griffey Jr. and Ken Griffey Sr. played together in 1990 for the Seattle Mariners.  In Hockey, Gordie Howe played with his sons Mark and Marty in 1979-80 for the Hartford Whalers. Gordie Howe came out of retirement to play with his sons, Mark and Marty Howe, when the WHA came into being.

There is a number of relevant examples in the American big leagues, most notably Ken Griffey Jr. and Ken Griffey Sr. in baseball, as well as Gordie, Mark and Marty Howe in hockey.


Bowls . Indoors this is played on carpet.

Outdoors it is played on grass, either Flat Green or Crown Green.

There aren't many professional players of Bowls, in any of the three disciplines, but they do exist.

The distance that the bowl has to travel is the same on both carpet and grass.

Of course it takes a lot more effort to send the bowl on grass, making the two disciplines very different to play.

The closest examples I can think of to tennis, where the same rules apply across significantly different surfaces are soccer, American football and baseball, all of which can be played on both natural and artificial turf.

Taking a slightly wider definition of "one sport", there are some more examples: Athletics events happen on the track and on the open road (marathons).

Professional cycling happens both in velodromes and on the open road.

Canoeing/kayaking happens on both flat and downhill courses.

Equestrian events happen both in the arena (dressage/show jumping) and outside (cross-country).

Volleyball happens both indoors and on sand.

Athletics (track and field) is contested across several surfaces.

The "road" disciplines are contested on city streets (concrete, tarmac, etc.) and cross-country is in parks (grass, rocks, trails, etc.), but those could be argued to be different from track and field.

Within specific disciplines, several events are contested on different surfaces.

Most notably, track events may be contested on 400m unbanked outdoor tracks and 200m banked (or unbanked) indoor tracks, even though the actual track surface may be the same indoors and out.

The shot put uses different equipment indoor and out because the shot is put into a sector marked in sand or grass outdoors, but is usually landing on a hard (or lightly padded) floor indoors.

The characteristics of the runways used for the pole vault, triple jump and long jump can vary significantly from indoors to outdoors.

Leaving aside the indoor/outdoor distinction, while all-weather synthetic surfaces are now the norm in athletics, until Mexico City in 1968 the Olympic track events were still contested on packed "cinder" tracks (with interesting results in Tokyo, where rainy weather made the inside lane of the track soft and uneven late in the distance races).

Also, some grass tracks are still maintained, although not often used for competition these days.

The rules of the sport allow for all of these surfaces.

Just another sport apart from the ones Philip Kendall mentioned, is cricket.

While the outfield has to be of grass, the pitch can be of varied types.

The condition of the pitch can vary from a green top to a completely dry,dusty surface.

Like tennis, the different conditions of the pitches will suit different players/teams.

The various types of pitches include: (non-exhaustive) Green top (significant grass cover)

Hard (bouncy surfaces)

Dry (dry grass cover) Dusty (dry without any grass cover)

Sticky (comparatively wet, generally due to rainy weather)

Rugby union is now played at the national and international level on grass and also 3G artificial pitches.

SQUASH is an example.

there are several playing surfaces: wood concrete plaster rubber panel(rare)

glass(rare)

More details can be found here .

Question: Other than tennis, which sports, at a professional level, are played on  intentionally  different surfaces?

What sports at a professional level are played on multiple surfaces?

Bowls, cycling and equestrian events are all practiced on different surfaces. Some forms of athletics are also practiced over more than one kind of surface, e.g. the marathon and cross-country running. In addition, some sports like cricket and rugby can be played on both real grass and artificial turk.

There is a great number of professional level sports played on multiple surfaces. These include bowls, America football and baseball, cycling, canoeing/kayaking, riding, cricket, rugby and squash. These sports are played in two or more surfaces, while different rules may apply. Special attention should be paid to athletics, which can take place on different tracks, on fields, but also on open roads.


As you mentioned, one of the primary differences between a Presta and Schrader valves are the diameters--with Schrader valves being slightly larger--and therefore the valve holes on bicycle rims are drilled to suit one size or another.

Your foremost concern with using a Presta valve in a rim drilled for a Shrader valve shouldn't be 'movement' of the valve stem, as geoffc suggested, but rather a 'hernia' of the tube through the excess space at high pressure, leading to a blowout.

Most mountain bike tires sit at a low pressure, therefore you will probably get away with it, however, there is a very inexpensive adapter, sometimes called a 'valve grommet', which is made out of rubber or metal and serves to make the valve hole small enough for a Presta valve to fit snugly.

It will also not come loose under high pressure, unlike geoffc's 'old tire' solution.

Yes you can.

Many presta tubes come with a grommet to allow you to use presta valve tubes in a wheel drilled for schraeder valves.

I do this all the time, basically use the presta nut on the inner side to avoid the tube getting "pinched" in the extra space, then if you can find another presta nut, screw that one to the outside where it's supposed to be.

Works like a charm.

I have not tried it, but consider, once the tube is inflated, the pressure will hold the valve stem pretty much in place.

The concern would be if the edge is rough enough that it would cut into the tube that protrudes.

Consider cutting an old tire and wrap the base of the stem with some old tube material and you would probably be fine.

As others have mentioned, there's ways to do it.

I'd just recommend not doing it.

I have more pressure loss problems with my Presta bikes than I do the Schrader equipped ones.

Strikes me as a downgrade rather than an upgrade.

The only advantage I find to the Presta is the size, which will let you run narrower wheels/tires.

It should work fine if the Presta tube is meant to inflate as large as a MTB tire is supposed to be.

I'd tape the valve to increase it's size.

I have done it and it worked fine.

Another alternative is to drill the correct size hole in the opposite side of the wheel - thus you can run presta or schrader in the same rim.

I inherited the wheels set up this way.

The person explained his reasoning that he preferred to just pump up the tire after a flat rather than changing tubes or patching.

My questions about puncturing the newly inflated tires immediately after got me a dim look since it sounded like he didn't bother to do any triage to remove the cause of the flats...

Back when I rode a road bike hybrid, I always used presta tubes with schraeder rims.

I can't say it worked 100% of the time, but I only had an issue once.

And that was across a couple years.

On my hybrid I have a schrader valve on the front wheel (the tube hasn't had a flat yet

so I've not changed the inner) and a presta valve on the back.

The nut that holds the presta valve to the rim seems to prevent any "hernia" from occurring, although occasionally I burst a rear tube when pumping it up too vigorously (it appears to "hernia" through the hole slightly and causes a burst around the base of the valve).

I always tighten the nut after inflation.

The reason for the presta valve on the back is that the size of inner tube I use only comes in presta valve versions at Halfords which is where, through pure force of habit, I end up buying replacement inner tubes.

I've been using a Presta valve in my front schrader rim since I picked up tubes last, because they were out of schraders in my rim size.

Haven't had any problems yet, knock on wood.

I have used both types of valves in tubes.

In my view the presta is strictly for narrow rims.

I prefer schrader valves my self for several reasons: the schrader valve tubes will hold high pressure the same as the presta.

They are easier to fill

they are easier to check the pressure using standard pressure guages found anywhere.

I say this based on more than fourty years of repairing and riding bicycles.

However, if you prefer presta then I can say that a presta valve in a schrader rim is usually no problem.

Question: I keep losing pressure in my tires, and among other things, I'm looking at the valves in the tubes. It's an old mountain bike with 26 inch tires. Can I use Presta tubes on rims drilled for Schrader valves ? I know the valve will be smaller than the hole and could cause issues there, but has anyone had success (or failures) with this?

Can I use a Presta tube in a Schrader rim?

Apparently there is no problem when using Presta tubes with Schrader rims. Many people do it and have no problems. However, some people advise against it as they say the loss of pressure using Presta tubes is more noticeable.

In most cases it is safe to use a Presta tube in Schrader rims, especially in mountain bikes that run on low pressure. However, it might not be recommended, as Presta may be optimal for narrow rims, but has more pressure losses, is more difficult to fill and cannot be checked with standard gauges.

It might not be recommended, as Presta may be optimal for narrow rims, but has more pressure losses, is ,ore difficult to fill and cannot be checked with standard gauges.


I thought spandex shorts looked weird too, until my wife bought me a pair with the padding.

Now, I can't ride in regular shorts at all!

The shorts with padding help protect your sensitive groin parts, as well help keep you cooler and drier (preventing nasty sores) by wicking the moisture (sweat) away from your body.

There's no binding or rubbing in the wrong areas, and all your jiggly parts are held securely in place.

And a big, important point about bike shorts

- you wear them without underwear.

Jerseys also come in tight and loose fitting material - I personally prefer the loose-fitting jerseys (I'm not exactly skinny enough to wear the tight jerseys).

Other than the moisture-wicking they provide, they also come in extremely visible colors, which is nice when you're out riding by yourself, especially if visibility is low.

There are a few good reasons for it.

More aerodynamic, we humans don't put out much power so every little bit helps Padded shorts.

You want these for anything longer than a short ride.

Most shorts with pads happen to be spandex.

Moisture wicking Read some things a few years ago about muscle fatigue when jiggling (rough road/mountain biking)

is greater than if you can compress the muscles a bit

so they don't move as much

If you don't like the way they look (and frankly, no man looks good in lycra shorts), you can wear a pair of lycra shorts with baggy shorts (or trousers) over the top -

that way you still get all the comfort benefits with none of the style penalties.

Depends on whether you want respect at the LBS or every other place you go into.

I'm cut-offs, T-shirts, and tennies.

I like going past the dudes that spent more on their clothes than I spent on my bike.

Sure, I look like a construction worker that's lost his driver's license

but I don't wear 420/tie-dyed either.

Misdirection and a contrarian streak.

As soon as someone says 'you gotta...'

I'm gone, and it is cheaper.

Clothes might make THE man but they don't make a man.

Go to a ski resort and look at the people coming off of the ends of the 'bunny runs', they've got all the fancy stuff.

"Just do it."

Because sweaty, crumpled cotton a) chafes and b) is pretty unhygienic.

Lycra ("spandex") doesn't bunch up, shifts sweat more effectively

and (if padded) takes a bit of the road buzz away.

I'm so used to wearing it the idea of looking strange doesn't even cross my mind.

Whatever you wear, make sure you wash it often.

The first few years of bike commuting, I was all about cotton shorts and shirts.

I thought lycra looked stupid, and was a waste of money.

Then I tried some lycra shorts.

What a difference.

My stuff didn't get chafed or squished on the 15km ride to work.

I kept cooler and drier.

Totally worth it.

I always wear lycra bike shorts now (the padding and hold-stuff-in-place ability are essential for comfort).

For those who aren't thrilled at dropping a bunch of money on expensive lycra shorts that look weird and make you uncomfortable, there is an alternative!

You can buy liners that do all that same amazing stuff (moistore wicking, bottom-padding, gonad-compressing) at a fraction of the price.

For example these: Men's Cycling Liners

I'm sure there are other alternatives, from other sources.

These will let you keep your baggies and have 90% of the benefits of $100 lycra shorts :)

Question: What's the reason for wearing biking clothes made of Spandex (Lycra)? They sure look pretty strange.

Why should I wear bicycle clothes made of spandex?

Spandex is the fabric of choice for cycling because it takes the sweat away from the body, holds the "jiggly" parts in place and provides padding, thus preventing chafing and soreness, as well as being more hygienic. Moreover, it ir more aerodynamic than cotton or other fabrics.

The main advantage of spandex wear is protecting and securing your sensitive parts, while keeping you cool and dry. Spandex does not seem to crumple, which could be an important factor in a long ride, and is more hygienic than materials like cotton. Arguably, spandex clothes also have an aerodynamic effect. Finally, most riding wear is made of spandex, so it is common among cyclist.

Arguably, spandex clothes have an aerodynamic effect.

Most riding wear is made of spandex, so it is common among cyclist.