user12629: I noticed that my USCF quick rating is lower than my USCF regular rating.  At first I thought maybe it was because I was relatively weaker at faster time controls, but it seemed like the difference was too large to be just that.  This got me to looking at the ratings of everyone in my section (It was the open section, there was another section of sub-1200 and unrated) of my most recent dual-rated tournament.  On average, the pre-event quick ratings of the 50-ish players in this tournament were 170 points below their regular ratings (and that even includes one player who never played quick before and was therefore given a provisional quick rating equal to his regular rating.)
It occurred to me that maybe I'm just in an area with local weirdness in the ratings, but that doesn't seem to be the case.  Wesley So has the highest regular rating in the nation, but his quick rating is 166 points lower than his regular.  The 100th best regular rating is 2474, but the 100th best quick rating is 2263, which is 211 points lower.
Although I know the player pools of the two rating systems are not identical, it would seem that the pools have significant overlap - all are USCF members who play in tournaments.  Initial quick ratings are literally based on the regular rating, if the player was already regular-rated.  And both rating systems appear to use the same algorithm to calculate ratings.
But despite that, quick ratings are significantly lower, apparently by nearly a full class.  Why are they so much lower, given the same algorithm and many of the same players?  And, assuming it's desirable that the ratings be similar, what could be done to correct this situation?

user20776: They are not really lower.  That depends on the person.  
Most lower rated players train the wrong way to be able to play speedier chess well, or at least better than very slow chess games.
GMs can play speed chess quite well and most would not have a lower speed rating than for slow OTB games.
Exacerbating the problem is digital clocks with all their weird add ons delays and similar gimmicks that drastically change the effect of playing faster on different people and their ratings.  
OTOH  I know a mere NM whose published speed rating is higher than his OTB.  So again,  it depends a lot more on the person than the ratings.
Also Exacerbating is the lumping of widely different speeds and related ability into one very wide category for the ratings.  
With more rating categories the ability vs speed would be better shown although for most players there will be a maximum where they are as good as they can be so slowing down the time control would not raise their ratings more.  

user33478: While floors contribute to it, the biggest reason for the difference is the fact that strong players are less likely to play quick rated tournaments as they improve. So their quick rating doesn't increase as fast as their regular. Here's an example scenario:
Tournament 1: Dual Rated. Regular Rating = 1000, Quick Rating = 998
Tournament 2: Regular rated only (longer time control). Regular rating: 1000 => 1100.
Tournament 3: Regular rated only (longer time control). Regular rating: 1100 => 1175.
So at the end of the day, your regular rating is 1175 but your quick remained at 998 . Then when you DO play a dual tournament again, you're quick rating is underrated and brings everyone else down. There are some crazy examples, of GMs like Awonder Liang with only 2100 quick ratings or so.
What USCF should do is automatically boost everyone's quick ratings to minimum 100 points lower than regular, if they want quick ratings to be accurate at all.

user32551: The reason is very simple: There are more players playing regular than quick time control.
What the rating algorithm says is that, within a player pool, the relative rating difference between two players should measure the relative strength between them. The weakest player in each pool always has a rating of 100 and every other player's rating represents their strength relative to the weakest player (assuming an ideal world where every player plays a lot). A rating in one player pool is incomparable to the rating in another player pool.
If we assume that each player pool has the same player strength distribution (e.g., a normal distribution), it follows that a player with the same percentile in both player pools gets an overall higher rating in the larger pool. Why? Because the larger the pool is, the more likely that the weakest player in the pool is weaker.
Your argument that regular and rapid pool have significant overlap don't matter. What matters is that they ultimate are very different in size. See the old stats: 65455 regular players vs 37162 quick players.
If you want to know whether you are stronger in regular or rapid, you can look up your percentiles in these two pools and compare them.

user12629: This may be partially due to ratings floors.
When a player hits his rating floor, his rating cannot go lower if he loses, but his opponent's rating can still go higher.  This adds ratings points into the system.
There is an absolute rating floor of 100 which nobody can go below. (For every event you play in and quarter-point you win over the board, this is raised by 1, to a maximum of 150.) Rating floors exist at every 100 points from 1200 to 2100, and these can be achieved by getting a rating at least 200 points above the floor. There's a rating floor at 2200 which can be earned by getting the Original Life Master title. And finally, if a player earns $4000 or more in an under-2000 section, their rating floor is set high enough so they become ineligible to win the prize again.
Regular and quick ratings both have ratings floors, but they are independent from each other. Most events with very large prizes are probably not quick-rated. And I don't think the Original Life Master title can be earned with a quick rating. This probably means that fewer people are at a floor with their quick rating, and that if they are, the floor is lower than it might otherwise be.  
To add rating points to the system, it is insufficient for a player to simply be at the floor - he must actually play games.  I would hypothesize that more regular-rated games are played than quick-rated games, especially at the 1200+ level where floors come into play.  I would also hypothesize that older players are more likely to be at a floor (because they won a large prize sometime on their life, because they once managed to raise their rating beyond its ordinary level, or because their skills are not what they once were) and that older players in particular play more regular games than quick games.
And if younger people play relatively more quick games, that may be another reason why quick ratings are lower.  Younger players are more likely to start with a very low rating but be rapidly improving.  When a player's ability improves, his rating lags behind, and his opponents will tend to lose rating points.  This tends to have a deflationary effect on ratings.

12629: <p>I noticed that my USCF quick rating is lower than my USCF regular rating.  At first I thought maybe it was because I was relatively weaker at faster time controls, but it seemed like the difference was too large to be just that.  This got me to looking at the ratings of everyone in my section (It was the open section, there was another section of sub-1200 and unrated) of my most recent dual-rated tournament.  On average, the pre-event quick ratings of the 50-ish players in this tournament were 170 points below their regular ratings (and that even includes one player who never played quick before and was therefore given a provisional quick rating equal to his regular rating.)</p>

<p>It occurred to me that maybe I'm just in an area with local weirdness in the ratings, but that doesn't seem to be the case.  Wesley So has the highest regular rating in the nation, but his quick rating is 166 points lower than his regular.  The 100th best regular rating is 2474, but the 100th best quick rating is 2263, which is 211 points lower.</p>

<p>Although I know the player pools of the two rating systems are not identical, it would seem that the pools have significant overlap - all are USCF members who play in tournaments.  Initial quick ratings are literally based on the regular rating, if the player was already regular-rated.  And both rating systems appear to use the same <a href="http://www.glicko.net/ratings/rating.system.pdf" rel="noreferrer">algorithm</a> to calculate ratings.</p>

<p>But despite that, quick ratings are significantly lower, apparently by nearly a full class.  Why are they so much lower, given the same algorithm and many of the same players?  And, assuming it's desirable that the ratings be similar, what could be done to correct this situation?</p>
 20776: <p>They are not really lower.  That depends on the person.  </p>

<p>Most lower rated players train the wrong way to be able to play speedier chess well, or at least better than very slow chess games.</p>

<p>GMs can play speed chess quite well and most would not have a lower speed rating than for slow OTB games.</p>

<p>Exacerbating the problem is digital clocks with all their weird add ons delays and similar gimmicks that drastically change the effect of playing faster on different people and their ratings.  </p>

<p>OTOH  I know a mere NM whose published speed rating is higher than his OTB.  So again,  it depends a lot more on the person than the ratings.</p>

<p>Also Exacerbating is the lumping of widely different speeds and related ability into one very wide category for the ratings.  </p>

<p>With more rating categories the ability vs speed would be better shown although for most players there will be a maximum where they are as good as they can be so slowing down the time control would not raise their ratings more.  </p>
 33478: <p>While floors contribute to it, the biggest reason for the difference is the fact that strong players are less likely to play quick rated tournaments as they improve. So their quick rating doesn't increase as fast as their regular. Here's an example scenario:</p>
<p>Tournament 1: Dual Rated. Regular Rating = 1000, Quick Rating = 998<br />
Tournament 2: Regular rated only (longer time control). Regular rating: 1000 =&gt; 1100.<br />
Tournament 3: Regular rated only (longer time control). Regular rating: 1100 =&gt; 1175.</p>
<p>So at the end of the day, your regular rating is 1175 but your quick remained at 998 . Then when you DO play a dual tournament again, you're quick rating is underrated and brings everyone else down. There are some crazy examples, of GMs like Awonder Liang with only 2100 quick ratings or so.</p>
<p>What USCF should do is automatically boost everyone's quick ratings to minimum 100 points lower than regular, if they want quick ratings to be accurate at all.</p>
 32551: <p>The reason is very simple: <strong>There are more players playing regular than quick time control.</strong></p>
<p>What the rating algorithm says is that, <strong>within a player pool</strong>, the relative rating difference between two players should measure the relative strength between them. <strong>The weakest player in each pool always has a rating of 100 and every other player's rating represents their strength relative to the weakest player</strong> (assuming an ideal world where every player plays a lot). A rating in one player pool is incomparable to the rating in another player pool.</p>
<p>If we assume that each player pool has the same player strength distribution (e.g., a normal distribution), it follows that a player with the same percentile in both player pools gets an overall higher rating in the larger pool. Why? Because <strong>the larger the pool is, the more likely that the weakest player in the pool is weaker</strong>.</p>
<p>Your argument that regular and rapid pool have significant overlap don't matter. What matters is that they ultimate are very different in size. See the old <a href="https://www.uschess.org/archive/ratings/ratedist.php" rel="nofollow noreferrer">stats</a>: 65455 regular players vs 37162 quick players.</p>
<p>If you want to know whether you are stronger in regular or rapid, you can look up your percentiles in these two pools and compare them.</p>
 12629: <p>This may be partially due to ratings floors.</p>

<p>When a player hits his rating floor, his rating cannot go lower if he loses, but his opponent's rating can still go higher.  This adds ratings points into the system.</p>

<p>There is an absolute rating floor of 100 which nobody can go below. (For every event you play in and quarter-point you win over the board, this is raised by 1, to a maximum of 150.) Rating floors exist at every 100 points from 1200 to 2100, and these can be achieved by getting a rating at least 200 points above the floor. There's a rating floor at 2200 which can be earned by getting the Original Life Master title. And finally, if a player earns $4000 or more in an under-2000 section, their rating floor is set high enough so they become ineligible to win the prize again.</p>

<p>Regular and quick ratings both have ratings floors, but they are independent from each other. Most events with very large prizes are probably not quick-rated. And I don't think the Original Life Master title can be earned with a quick rating. This probably means that fewer people are at a floor with their quick rating, and that if they are, the floor is lower than it might otherwise be.  </p>

<p>To add rating points to the system, it is insufficient for a player to simply be at the floor - he must actually play games.  I would hypothesize that more regular-rated games are played than quick-rated games, especially at the 1200+ level where floors come into play.  I would also hypothesize that older players are more likely to be at a floor (because they won a large prize sometime on their life, because they once managed to raise their rating beyond its ordinary level, or because their skills are not what they once were) and that older players in particular play more regular games than quick games.</p>

<p>And if younger people play relatively more quick games, that may be another reason why quick ratings are lower.  Younger players are more likely to start with a very low rating but be rapidly improving.  When a player's ability improves, his rating lags behind, and his opponents will tend to lose rating points.  This tends to have a deflationary effect on ratings.</p>
