user38: Grouping of initial moves of a chess game are well known, though I've never seen analysis of the worst possible opening move, any thoughts? If so, please provide more than just a move, but the exact reason why such a move would be the worst assuming such a move was against a GM.

user23691: Just tell you one thing, 1.f3 is bad, it does not control the center actually, it stopped the knight, and it place the king in danger. Sometimes even followed by 2.Kf2, I think this is the hammerschlag variation, further weakening the king, this is to laugh at beginners, but no one have win me with it yet. 

user19861: I would say 1. Nh3. 
1.f3 is bad however after g3 white is only down a couple of tempos and has a somewhat reasonable position. 
1.Nh3 allows black the potential to to wreck white's pawn structure and even threaten a very quick mate. Yes, white can avoid that with Ng4->Nf3 but you've wasted two tempos when you could have done the same thing with 1.Nf3  
White is in a struggle for equality after 1.Nh3 and is one slip away from losing the game for the next several moves. Even if white does play perfectly, he has thrown away several tempi for no reason and allowed an equal game. 

user23908: 1.f3
PROS
The only pros of the opening is some small center support.
CONS

This opening weakens the king's safety. The f pawn is an important shelter of the e1-h4 diagonal and the g1-b7 diagonal so moving it makes the kingside pawn structure destroyed.
This opening don't open any lines fo development, and it blocked the knight!
Wasted tempo.

SUGGESTION FOR PLAYING
I do not suggest it for anyone
1.h4 and 1.a4
PROS
None
CONS

Doesn't open any lines nor development.
Weakens pawn structure.
Wasted tempo.

SUGGESTION FOR PLAYING
I do not suggest it for anyone
1.h3 and 1.a3
PROS
Does not weaken anything.
CONS

Wasted tempo.
No development lines.

SUGGESTION FOR PLAYING
For white players who want to play black.
1.Na3
PROS

It can develop to c4 or c2 but that would waste some tempos.
Support c pawn, but can't the c pawn move already?

CONS

After 1...d5 and an exchange the pawn structure is lost.
Wasted tempo.

SUGGESTION FOR PLAYING
Only in blitz.
1.Nh3
PROS

It can use another tempo to go to f4.
I'm surprised at nobody mentioning it, but it protects f2!

CONS

Wasted tempo
After 1...e5 and exchange the pawn structure is lost... and the f2 protection is gone!

SUGGESTIONS FOR PLAYING
Only in blitz.
1.c3
PROS
Support d4
CONS

No development and blocks knight
Wasted tempo.

SUGGESTION FOR PLAYING
For Caro Kann players.
1.g4
PROS
Open lines for bishop development
CONS

The g pawn is undefended.
Weakens kingside.

SUGGESTION FOR PLAYING
Only in blitz.
The third most bad is 1.Na3?! and 1.Nh3?!
The second most bad is 1.h4?! and 1.a4?!
The most bad is 1.f3?!

user118: The idea of the opening moves is to allow an early development of pieces. Therefore the worst moves would be the ones that allow you the least opportunity to do so. So I would say 1. a3, 1. h3, and 1. f3 would be the worst. You not only lose the race in developing your pieces quickly (the only piece you can develop after these moves is the knight), but you also give up control on the central squares.

user47: I would say 1. Na3.  The reason is that it is the most useless move as far as building a setup around it.  Even moves mentioned like 1. h4 and 1. f3 can be useful in some contexts - 1. f3 can be useful if you play d4 and Nc3 and plan e4.  1. h4 can be useful because you discourage your opponent from fianchettoing his bishop, and you can push it again for cramping effect.  It is difficult, however, to imagine any setup where 1. Na3 is a helpful move, and furthermore after ...e5 you will have to move the knight or play b3 to avoid getting doubled a-pawns, which are probably the worst doubled pawns since the open b-file is rarely useful and they are not supporting anything or guarding any important squares.

user919: I'm just trying to protect a move that's mentioned above as being perhaps one of the worst. Grandmaster Mednis years ago wrote a little opening theory book ("How to play good opening moves," Edmar Mednis, ISBN-13: 978-0679141099) in which he states that
1.g3
is one of White's perfect opening move choices, when followed by
2.Bg2.
He does mention some of White's awful first move choices, but doesn't rank their badness.

user15129: 1. g4 ... 2. f3??
This is a horrendous opening (especially in combination with the second move) because it severely undermines the ability to castle on the king's side, very aggressively throws a pawn into action where it has no defenders and isn't helping any cause in particular. 
g4 allows to fianchetto the light-square bishop, as well as hide the dark square bishop behind it later, if needed, which is an odd, but somewhat redeeming quality, but as soon as it's followed by 2. f3, the light-square bishop is entombed and white have ZERO center control or active development for whole 3 tempi, allowing black to gain a MASSIVE center presence and advantage. And after 1. ...d5 followed by 2. ...h5 the g4 square now belongs to the black and sets a great entry point to a king-side attack. If white tried to take on g5, black now has a semi-open file without ever moving the rook. Thanks for that! 
Such a horrible game would typically go like this: 1. g4 d5  2. f3 e5  3. Bg2 h5 - and black is 2+ points in the lead without having taken a single piece yet, according to any decent engine. White would need a major miracle and a blunder from black to have any chance to recover from that.
Example: Hou Yifan throws game

user35: I agree 1. f3 is quite bad, but 1. Na3 and 1. Nh3 aren't pretty either, especially as they have to move again to avoid a doubled pawn after ...d5 or ...e5.

user7615: 1.Nh3 and 1.Na3 (Ammonia attack, Sodium attack) are REALLY bad. It breaks the "move one piece one time" rule, and 1.Nh3 blocks h3, a good move to prevent back-rank mate.

user107: 1. h4 has been deemed the worst move by John Watson (author of the Mastering the Chess Openings series). Other people are saying 1. h3 and 1. a3. That is not true. Michael Basman is a noted unorthodox player that opens with 1. a3/h3, etc. and is rated >2400. 1. a3/h3 come out to be useful in a variety of openings, but it's certainly not what I would start with.

user7500: The worst move is 1. resigns. It goes from equal to lost in one move, much worse than moves like 1. f3 which go from equal to slightly worse.

user4362: For an objective take on this question, one might take a look at the Chessok Opening Tree:

1.f3 -0.33
1.g4 -0.29
1.Nh3 -0.22
1.b4 -0.18
1.h4 -0.18

Given that white should be able to achieve a plus of 0.11 (according to the Tree) these are the only moves that not only lose the first move advantage but more than reverse it.
Of course these computer evaluations have to be taken with a grain of salt, but they do bear out the intuition of experienced players and provide some food for thought (especially to adherents of the Sokolski …).

user14079: The other moves cited, especially 1.f3, are bad, but I would rather plead the case of the ugly Grob opening, 1.g4?.
Pawns do not go back, so this double step weakening is much more committing than a one step pawn move. After, say 1...e5, White has not only lost time, he has also:

Self-destroyed the most natural shelter for his own king, reached by short castle.
created weaknesses for himself, as Pg4 can and will be targeted by Bc8 or Ph5.
got himself a disadvantage in the fight for the center.

If, in some kind of handicapped game, I could choose my opponent's first move in order to maximize my chances, I would rather force him to play 1.g4 than anything else.

user86: I agree with Andrew on 1. f3 (Barnes Opening).  No first move can be decisively wrong, but some first moves are questionable.  In Chess Opening Theory (Wikibooks):

Quite a rarely played passive starting move that gives up White's first move advantage. White's position is slightly weakened by the White King exposure to a check on the h4 - e1 diagonal. The kingside Knight's favourite developing square f3, is also not currently possible. In fact, this is arguably the worst possible first move by White.
No stats as 1. f3 occurs rarely among serious chess players.

Next on the list would probably be 1. h4 (Desprez Opening):

1. h4 is a rather useless move that does nothing to assist the important central squares. No top masters have ever used it in professional play, although some, most notably Hikaru Nakumura, play it during blitz. It could be said that White has made his position worse, as castling kingside is now less attractive.
This move is rarely seen among serious chess players.


user12: 1. f3 is almost certainly the single worst move.  It irrevocably weakens white's king position without doing anything useful.  
Other moves like 1. b3 and 1. g3 prepare to develop a bishop, so they're not so bad.  1. c3 doesn't do too much for white, but it also doesn't hurt him.
1. a4 and 1. h4 both ignore the center, but they do help develop the rooks, and there are positions where 1. a4/h4 can be useful (especially when the kings have castled on opposite sides of the board.

38: <p>Grouping of initial moves of a chess game are well known, though I've never seen analysis of the worst possible opening move, any thoughts? If so, please provide more than just a move, but the exact reason why such a move would be the worst assuming such a move was against a GM.</p>
 23691: <p>Just tell you one thing, 1.f3 is bad, it does not control the center actually, it stopped the knight, and it place the king in danger. Sometimes even followed by 2.Kf2, I think this is the hammerschlag variation, further weakening the king, this is to laugh at beginners, but no one have win me with it yet. </p>
 19861: <p>I would say 1. Nh3. </p>

<p>1.f3 is bad however after g3 white is only down a couple of tempos and has a somewhat reasonable position. </p>

<p>1.Nh3 allows black the potential to to wreck white's pawn structure and even threaten a very quick mate. Yes, white can avoid that with Ng4->Nf3 but you've wasted two tempos when you could have done the same thing with 1.Nf3  </p>

<p>White is in a struggle for equality after 1.Nh3 and is one slip away from losing the game for the next several moves. Even if white does play perfectly, he has thrown away several tempi for no reason and allowed an equal game. </p>
 23908: <p><em><strong>1.f3</strong></em></p>
<p><em><strong>PROS</strong></em>
The only pros of the opening is some small center support.</p>
<p><em><strong>CONS</strong></em></p>
<ol>
<li>This opening weakens the king's safety. The f pawn is an important shelter of the e1-h4 diagonal and the g1-b7 diagonal so moving it makes the kingside pawn structure destroyed.</li>
<li>This opening don't open any lines fo development, and it blocked the knight!</li>
<li>Wasted tempo.</li>
</ol>
<p><em><strong>SUGGESTION FOR PLAYING</strong></em>
I do not suggest it for anyone</p>
<p><em><strong>1.h4 and 1.a4</strong></em></p>
<p><em><strong>PROS</strong></em>
None</p>
<p><em><strong>CONS</strong></em></p>
<ol>
<li>Doesn't open any lines nor development.</li>
<li>Weakens pawn structure.</li>
<li>Wasted tempo.</li>
</ol>
<p><em><strong>SUGGESTION FOR PLAYING</strong></em>
I do not suggest it for anyone</p>
<p><em><strong>1.h3 and 1.a3</strong></em></p>
<p><em><strong>PROS</strong></em>
Does not weaken anything.</p>
<p><em><strong>CONS</strong></em></p>
<ol>
<li>Wasted tempo.</li>
<li>No development lines.</li>
</ol>
<p><em><strong>SUGGESTION FOR PLAYING</strong></em>
For white players who want to play black.</p>
<p><em><strong>1.Na3</strong></em></p>
<p><em><strong>PROS</strong></em></p>
<ol>
<li>It can develop to c4 or c2 but that would waste some tempos.</li>
<li>Support c pawn, but can't the c pawn move already?</li>
</ol>
<p><em><strong>CONS</strong></em></p>
<ol>
<li>After 1...d5 and an exchange the pawn structure is lost.</li>
<li>Wasted tempo.</li>
</ol>
<p><em><strong>SUGGESTION FOR PLAYING</strong></em>
Only in blitz.</p>
<p><em><strong>1.Nh3</strong></em></p>
<p><em><strong>PROS</strong></em></p>
<ol>
<li>It can use another tempo to go to f4.</li>
<li>I'm surprised at nobody mentioning it, but it protects f2!</li>
</ol>
<p><em><strong>CONS</strong></em></p>
<ol>
<li>Wasted tempo</li>
<li>After 1...e5 and exchange the pawn structure is lost... and the f2 protection is gone!</li>
</ol>
<p><em><strong>SUGGESTIONS FOR PLAYING</strong></em>
Only in blitz.</p>
<p><em><strong>1.c3</strong></em></p>
<p><em><strong>PROS</strong></em>
Support d4</p>
<p><em><strong>CONS</strong></em></p>
<ol>
<li>No development and blocks knight</li>
<li>Wasted tempo.</li>
</ol>
<p><em><strong>SUGGESTION FOR PLAYING</strong></em>
For Caro Kann players.</p>
<p><em><strong>1.g4</strong></em></p>
<p><em><strong>PROS</strong></em>
Open lines for bishop development</p>
<p><em><strong>CONS</strong></em></p>
<ol>
<li>The g pawn is undefended.</li>
<li>Weakens kingside.</li>
</ol>
<p><em><strong>SUGGESTION FOR PLAYING</strong></em>
Only in blitz.</p>
<p><em><strong>The third most bad is 1.Na3?! and 1.Nh3?!</strong></em>
<em><strong>The second most bad is 1.h4?! and 1.a4?!</strong></em>
<em><strong>The most bad is 1.f3?!</strong></em></p>
 118: <p>The idea of the opening moves is to allow an early development of pieces. Therefore the worst moves would be the ones that allow you the least opportunity to do so. So I would say <code>1. a3</code>, <code>1. h3</code>, and <code>1. f3</code> would be the worst. You not only lose the race in developing your pieces quickly (the only piece you can develop after these moves is the knight), but you also give up control on the central squares.</p>
 47: <p>I would say <code>1. Na3</code>.  The reason is that it is the most useless move as far as building a setup around it.  Even moves mentioned like <code>1. h4</code> and <code>1. f3</code> can be useful in some contexts - <code>1. f3</code> can be useful if you play <code>d4</code> and <code>Nc3</code> and plan <code>e4</code>.  <code>1. h4</code> can be useful because you discourage your opponent from fianchettoing his bishop, and you can push it again for cramping effect.  It is difficult, however, to imagine any setup where <code>1. Na3</code> is a helpful move, and furthermore after <code>...e5</code> you will have to move the knight or play <code>b3</code> to avoid getting doubled a-pawns, which are probably the worst doubled pawns since the open b-file is rarely useful and they are not supporting anything or guarding any important squares.</p>
 919: <p>I'm just trying to protect a move that's mentioned above as being perhaps one of the worst. Grandmaster Mednis years ago wrote a little opening theory book (&quot;<em>How to play good opening moves</em>,&quot; Edmar Mednis, ISBN-13: 978-0679141099) in which he states that</p>
<p>1.g3</p>
<p>is one of White's <em>perfect</em> opening move choices, when followed by</p>
<p>2.Bg2.</p>
<p>He does mention some of White's <em>awful</em> first move choices, but doesn't rank their badness.</p>
 15129: <p><code>1. g4</code> ... <code>2. f3??</code></p>

<p>This is a horrendous opening (especially in combination with the second move) because it severely undermines the ability to castle on the king's side, very aggressively throws a pawn into action where it has no defenders and isn't helping any cause in particular. </p>

<p><code>g4</code> allows to fianchetto the light-square bishop, as well as hide the dark square bishop behind it later, if needed, which is an odd, but somewhat redeeming quality, but as soon as it's followed by <code>2. f3</code>, the light-square bishop is entombed and white have ZERO center control or active development for whole 3 tempi, allowing black to gain a MASSIVE center presence and advantage. And after <code>1. ...d5</code> followed by <code>2. ...h5</code> the <code>g4</code> square now belongs to the black and sets a great entry point to a king-side attack. If white tried to take on <code>g5</code>, black now has a semi-open file without ever moving the rook. Thanks for that! </p>

<p>Such a horrible game would typically go like this: <code>1. g4 d5  2. f3 e5  3. Bg2 h5</code> - and black is 2+ points in the lead without having taken a single piece yet, according to any decent engine. White would need a major miracle and a blunder from black to have any chance to recover from that.</p>

<p>Example: <a href="https://www.youtube.com/watch?v=GC6lJJKvl-4" rel="noreferrer">Hou Yifan throws game</a></p>
 35: <p>I agree <code>1. f3</code> is quite bad, but <code>1. Na3</code> and <code>1. Nh3</code> aren't pretty either, especially as they have to move again to avoid a doubled pawn after <code>...d5</code> or <code>...e5</code>.</p>
 7615: <p>1.Nh3 and 1.Na3 (Ammonia attack, Sodium attack) are REALLY bad. It breaks the "move one piece one time" rule, and 1.Nh3 blocks h3, a good move to prevent back-rank mate.</p>
 107: <p><code>1. h4</code> has been deemed the worst move by John Watson (author of the Mastering the Chess Openings series). Other people are saying <code>1. h3</code> and <code>1. a3</code>. That is not true. Michael Basman is a noted unorthodox player that opens with <code>1. a3/h3</code>, etc. and is rated >2400. <code>1. a3/h3</code> come out to be useful in a variety of openings, but it's certainly not what I would start with.</p>
 7500: <p>The worst move is 1. resigns. It goes from equal to lost in one move, much worse than moves like 1. f3 which go from equal to slightly worse.</p>
 4362: <p>For an objective take on this question, one might take a look at the <a href="http://chessok.com/?page_id=352" rel="noreferrer">Chessok Opening Tree</a>:</p>
<ol>
<li>1.f3 -0.33</li>
<li>1.g4 -0.29</li>
<li>1.Nh3 -0.22</li>
<li>1.b4 -0.18</li>
<li>1.h4 -0.18</li>
</ol>
<p>Given that white should be able to achieve a plus of 0.11 (according to the Tree) these are the only moves that not only lose the first move advantage but more than reverse it.<br />
Of course these computer evaluations have to be taken with a grain of salt, but they do bear out the intuition of experienced players and provide some food for thought (especially to adherents of the Sokolski …).</p>
 14079: <p>The other moves cited, especially 1.f3, are bad, but I would rather plead the case of the ugly Grob opening, 1.g4?.</p>
<p>Pawns do not go back, so this double step weakening is much more committing than a one step pawn move. After, say 1...e5, White has not only lost time, he has also:</p>
<ul>
<li>Self-destroyed the most natural shelter for his own king, reached by short castle.</li>
<li>created weaknesses for himself, as Pg4 can and will be targeted by Bc8 or Ph5.</li>
<li>got himself a disadvantage in the fight for the center.</li>
</ul>
<p>If, in some kind of handicapped game, I could choose my opponent's first move in order to maximize my chances, I would rather force him to play 1.g4 than anything else.</p>
 86: <p>I agree with Andrew on <a href="http://en.wikibooks.org/wiki/Chess_Opening_Theory/1._f3" rel="noreferrer"><code>1. f3</code></a> (Barnes Opening).  No first move can be decisively wrong, but some first moves are questionable.  In <em><a href="http://en.wikibooks.org/wiki/Chess_Opening_Theory/1._f3" rel="noreferrer">Chess Opening Theory</a></em> (Wikibooks):</p>
<blockquote>
<p>Quite a rarely played passive starting move that gives up White's first move advantage. White's position is slightly weakened by the White King exposure to a check on the h4 - e1 diagonal. The kingside Knight's favourite developing square f3, is also not currently possible. In fact, this is arguably the worst possible first move by White.</p>
<p>No stats as <code>1. f3</code> occurs rarely among serious chess players.</p>
</blockquote>
<p>Next on the list would probably be <a href="http://en.wikibooks.org/wiki/Chess_Opening_Theory/1._h4" rel="noreferrer"><code>1. h4</code></a> (Desprez Opening):</p>
<blockquote>
<p><code>1. h4</code> is a rather useless move that does nothing to assist the important central squares. No top masters have ever used it in professional play, although some, most notably Hikaru Nakumura, play it during blitz. It could be said that White has made his position worse, as castling kingside is now less attractive.</p>
<p>This move is rarely seen among serious chess players.</p>
</blockquote>
 12: <p><code>1. f3</code> is almost certainly the single worst move.  It irrevocably weakens white's king position without doing anything useful.  </p>

<p>Other moves like <code>1. b3</code> and <code>1. g3</code> prepare to develop a bishop, so they're not <em>so</em> bad.  <code>1. c3</code> doesn't do too much for white, but it also doesn't hurt him.</p>

<p><code>1. a4</code> and <code>1. h4</code> both ignore the center, but they do help develop the rooks, and there are positions where <code>1. a4/h4</code> can be useful (especially when the kings have castled on opposite sides of the board.</p>
