What does "knights have no long-lasting support points" mean in this game? In this article on pawn structure, the author uses this game as example:

[Event "Prague 2008"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "David Navara"]
[Black "Vladimir Kramnik"]
[Result "0-1"]
[SetUp "1"]
[FEN "rnbq1rk1/pp2bppp/2p5/2npP3/3N1P2/2NB4/PPP3PP/R1BQ1RK1 b - - 0 9"]
[WhiteElo ""]
[BlackElo ""]
[ECO ""]
[CurrentPosition "rnbq1rk1/pp2bppp/2p5/2npP3/3N1P2/2NB4/PPP3PP/R1BQ1RK1 b - - 0 9"]

9...Nxd3 10.Qxd3 f5! 11.Nb3 Na6 12.Be3 Nc7 { Defends d5 (making ...c5 possible) and, at the right time, move the knight to e6. } 13.Ne2 b6 14.Nbd4 Ba6 15.Qd2 Qe8 16.c3 c5 { The d4-knight is pushed back to the cold, dark, hellish vistas that occurs when you realize that you’ve been thoroughly outplayed. } 17.Nf3 Rd8 18.Rfd1 Ne6 { and Black has created a dream for Black. Here’s the rest of the game: } 19.a4 h6 20.a5 Qb5 21.Ng3 bxa5 22.Qc2 g6 23.Qa4 Qxa4 24.Rxa4 d4 25.cxd4 cxd4 26.Nxd4 Bc5 27.Rxa5 Nxd4 28.Rxa6 Nf3+ 29.Kf2 Bxe3+ 30.Kxf3 Rxd1 31.Kxe3 Rfd8 32.Rxg6+ Kh7 33.Ra6 R8d3+ 34.Kf2 R1d2+ 35.Ne2 Rd7 36.e6 Rb7 37.Ke3 Rdxb2 38.Nd4 R2b6 39.Rxb6 Rxb6 40.e7 Rb8 41.Nxf5 a5 42.Nd4 a4 43.Nc6 Re8 44.Kd4 Kg7 45.Kc4 Kf7 46.Kb4 Ra8 47.Ka3 Ra6 48.Nb4 Rd6 49.Kxa4 Kxe7 50.Kb5 Rd2 51.g4 Rxh2 52.Kc5 Ke6 53.Kd4 Rh4 54.f5+ Kf7 55.Ke5 Rxg4 56.Nd5 Ra4 57.Nc3 Rb4 58.Ne4 h5 59.Ng5+ Kg8 60.f6 h4 61.Kf5 Rb5+ 62.Kg6 Rxg5+ { , 0-1 }  0-1

Then, when explaining why 10... f5! is a good movement, he says:

  The idea is that White’s knights have no long-lasting support points

What does this mean? how does the pawn on f5 achieve or help to this?

It is not that the pawn on f5 achieves/helps this. As far as I understand Silman, what he means is that black can play 10...f5, which gives white a protected passed pawn and which weakens the square e6, because white's knights will eventually be driven away when black plays c5, etc

Look at the position after 18.... Ne6 for instance. Black has achieved everything he wanted: blocked the passed pawn with his knight, gained space in the center through his pawns on c5 and d5, has a very strong bishop on a6.... The white knights on the other hand have no good squares  to go to and also the other pieces of white don't do much.

Consider the opposite situation, where the white knights could not be driven away (i.e. where they have long-lasting support points). For instance if white had a (protected) pawn on c5 in the initial position, black would have a very hard time after f5 because the knight on d4 attacks f5, c6 and hinders black from blocking the passed pawn by placing a piece on e6. It also hinders black from play on the queenside (because the c6 pawn might be weak or hanging). Furthermore the second white knight could be moved to e3 further adding to the pressure.

So essentially what Silman is saying is that Kramnik can play 10...f5 which is against the principle of not giving your opponent protected passed pawns, because in this situation here, white cannot make use of this asset. The knights will be kicked away and black's play on the queenside is more valuable than the protected passed pawn, which often only pays off in an endgame.


Is Houdini 6 a Stockfish clone? I've been hearing this claim being bandied about quite a lot and I'm wondering if there's any substance to it. Apparently the details are in a certain thread on Talkchess, but it's not viewable to non-logged in readers, and it won't let me register. There are no details about this on the Houdini Wikipedia page either.

Can anyone give a summary of the allegations and the evidence for (and against) it?

Yes.

The search, evaluation, etc., are almost identical to Stockfish, with the notable exception of being rewritten in Dutch. A number of Stockfish developers, including former maintainers, have noted as such. To hide its origins, code was included that multiplied the node count by 8/7. Exploiting modular arithmetic tricks and archived Houdini games, this exact code was shown to be present in the release version of Houdini. The alleged performance improvements over Stockfish go away after removing this trick.

The leaked source code was compiled by Ed Schroder and found to have a 1:1 correspondence with Houdini in a vast number of test positions, while others, like Simon Guenther, have found that the leaked code behaves identically in the start position even up to high depths.

There were changes, but Mark Lefler, developer of Komodo, noted that a number ofaa changes were simply adding features reverse engineered from Komodo. In fact, in one file, evaluatie.cpp, you can spot the naming conventions used by the Hex-Rays decompiler.

Other features were unique, but minor. For example, the licensing system was not from Stockfish. However, the code came from TurboPack and was translated into C++, so it's not clear that that was original work, either.

Adjusting for the time of release, the version of Stockfish on GitHub at the time of Houdini  5's release was more or less equal in strength to Houdini 5. Later, when Houdini 6 was released, this was also true. (Source: nextchessmove's elo data + CCRL data)

In other words, Houdini did not notably build upon Stockfish in any meaningful way. The main reason it looks different is because of the Dutch translation and the fact that Stockfish has evolved significantly since Houdart last touched the Stockfish codebase.


Are there any engines that present evaluations based on probability of finding moves? All engines I'm aware of focus on finding the best moves to win the position. I'm curious whether there are any that exist that attempt to present an honest evaluation of a position, with human capabilities in mind. For example, with each candidate move, associate a weighted probability that indicates the likelihood a human is to actually find a given move on the board.

I'm thinking of situations where computers can find winning lines, but the key moves are so counterintuitive or unnatural that most humans would never consider them.

This is clearly a challenging computer science task. I'm also not even sure there's a good use case for such an engine. But, I'm curious.

No engine do what you describe because it’s too hard to code a imperfect human brain. Estimating positional complexity at humans level is also quite hard.


How to work out quiet positions? I am a good player when I have a plan. If I have a certain goal in mind, I can see the way to it. But in quiet, planless, positions, I have difficulty as an attacking and tactical player. What is the best way to cope with them.

When there is no concrete plan of action possible, the general plan should be to -

  Improve the position of your pieces
  Trade off bad pieces if possible
  Try to create weaknesses in your opponent's position
  Keep your king safe and see if the enemy's king position can be compromised.


Misplaying (?) the Guicco Pianissimo; is 14. d4 correct? I recently lost an OTB game against a strong player (USCF) as white in the Guicco Pianissimo and have a few questions about it, especially 14. d4!?. Feedback/criticism are appreciated greatly.

Thanks everyone

[FEN ""]
[Event "Local Tournament"]
[Site "?"]
[Date "????.??.??"]
[Round "4"]
[White "Me"]
[Black "Opponent"]
[Result "0-1"]
[WhiteElo "1800"]
[BlackElo "2300"]
[ECO ""]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d3 { I generally enjoy playing these positions for white. } 4...Bc5 5.O-O d6 6.c3 a6 7.a4 Ba7 8.Nbd2 O-O 9.b4!? { Do I really have enough time to play this expansive move here? Perhaps it's better to continue by focusing on development. } ( 9.Bb3 { Followed by Nc4 and Be3 is probably the best way to get the dark-squared bishop into the game. } ) 9...Ne7 10.Bb3 Ng6 11.Nc4 b5! { With my pawn on b4, it seems like this advance blocks my position much more severely than it would otherwise. } 12.axb5 axb5 13.Ne3 { Here, I'm not entirely sure if e3 is the best square. } ( 13.Na5 { this move creates some queenside threats, but I'm worried that the knight will become out of play. } ) 13...Nf4 { A nice outpost, since I can't really play } 14.d4!? { Open the position straight away, or wait? I felt that I almost had no strategic ideas left besides playing this move, but perhaps I should attempt to improve my position beforehand. } ( 14.Qc2 Bb7 { I didn't like this method, because I felt paralyzed by the pressure on the e4 square. } ) ( 14.Re1 { Perhaps I should continue preparatory moves like Re1, Qc2/Qd2 and Bb2, anticipating the opening of the position. } ) 14...Qe8 ( 14...Nxe4 15.Qc2 { Doesn't work due to } 15...Nxc3! { So, how would I have actually been able to proceed after 14... Nxe4? } ) 15.dxe5? { I feel that relieving this tension is a mistake. Re1 looks interesting, keeping a lot of tactical ideas alive in the center. } ( 15.Re1 Nxe4 16.Qc2 Bb7 17.Nf5 { Looks like a respectable position. } ) ( 15.Nd5 N4xd5 16.Bxd5 Nxd5 17.exd5 { Also looks interesting, with black's misplaced queen and undeveloped c8-bishop. } ) 15...dxe5 16.Nd5?? { Now here I'm missing a tactic that I should not miss. Being exhausted isn't a perfect excuse, but I was quite physically exhausted during this game. At this point, I also realize that playing Bb2 far in advance would have eliminated these tactics on the a-file. } ( 16.Nd5 ) ( 16.Bb2 { Might still hold an equal battle } 16...Nxe4? 17.Bd5 Nxd5 18.Qxd5 { Forking } ) 16...N4xd5 17.exd5 Bxf2+! 18.Rxf2 Rxa1 19.Ra2 { I don't know what else I can do here besides try to trade the strong rook. } 19...Rxa2 20.Bxa2 Bg4 21.h3 Bh5 22.g4 Bg6 23.d6 cxd6 24.Qxd6 Qd8 ( 24...Qa8 { Makes things easier. } ) 25.Qxd8 Rxd8 26.Kf2 Ne4+ 27.Ke3 Nxc3 28.Bb3 Rd3+ { And the bishop falls. } ( 28...Rd3+ 29.Kf2 Ne4+ )  0-1

I haven't played the Italian game in some time, but my thoughts are in the replayer below:

[FEN ""]

  1. e4             e5
  2. Nf3            Nc6
  3. Bc4            Nf6
  4. d3 {You said you like these kinds of positions. Given that the first game of yours I analysed started with 1.d4, it may be advisable to stick to a smaller opening repertoire, e.g. always starting with 1.e4. Either way, I think you played the opening fine}             Bc5
  5. O-O {5.Be3 is common in the Italian game, hoping for 5...Bxe3 6.fxe3, strengthening the centre and giving an open file for the rook. But it is a bit double edged, as sometimes black can play Ng4}            d6
  6. c3             a6
  7. a4 {7.d4 is the key advance that you have prepared for, so I'm not sure why you didn't play it} (7.d4 exd4 8.cxd4 Bb6)            Ba7
  8. Nbd2 {The queenside bishop and knight are the worse pieces in the game for you. If you had played 7.d4, then the c3 square may have been available for the knight and the bishop could come to e3 or g5}          O-O
  9. b4             Ne7
 10. Bb3 {It might be an unconventional square for the bishop in the Italian game, but you shouldn't be moving the same 2 pieces over-and-over again. I don't know what your Bb3 and Nc4 plans aimed to achieve} (10.Bb2)            Ng6
 11. Nc4            b5
 12. axb5           axb5
 13. Ne3 {13.Ne3 isn't such a bad move, as long as either Bb2 or Nc2 are played to defend the a1 rook. 13.Na5 doesn't achieve much as the c6 square can't be occupied}           Nf4
 14. d4             Qe8
 15. dxe5           dxe5
 16. Nd5            N4xd5
 17. exd5           Bxf2+
 18. Rxf2           Rxa1
 19. Ra2            Rxa2
 20. Bxa2           Bg4
 21. h3             Bh5
 22. g4             Bg6
 23. d6 {This loses a pawn. I would try 23. Qe2} cxd6 (23...cxd6 24.Nh4 Qc6 25.Nxg6 hxg6 26.Bb2 Qe4 27.Bc1 Ra8 28.Bb3)
 24. Qxd6 {This loses 2 pawns. Preferable is 24. Nh4} Qd8 (24...Qa8 25.Nxe5 Rd8 26.Qb6 Rd1+ 27.Kf2 Rxc1 28.Kg3 Rxc3+ 29.Kh4 Rc2 30.Nxg6 hxg6)
 25. Qxd8           Rxd8
 26. Kf2 {I don't know why you advanced the king into check. I would have tried to activate the dark square bishop with 26.Bg5}           Ne4+
 27. Ke3            Nxc3
 28. Bb3            Rd3+
 0-1

Summary

You didn't misplay the opening other than not playing the d4 break
I'm guessing that you have quite a wide repertoire seeing as you pay both 1.e4 and 1.d4. This is fine, but you may want to focus on just one
You moved the same pieces (queenside knight and light square bishop) rather than developing the dark square bishop
Towards the end there were multiple tactical blunders such as 26. Kf2, rather than 26. Bg5. The game would have still been tough, but those tactics partly stem from never developing the dark square bishop


2 Knights against 1 pawn (endgame) Why is it important to leave the opponent's pawn in this situation?

From over 7kk games only 426 ends with KNN against KP, of which 286 games (67.1%) is draw.

In the two knights endgame, how should we block the pawn to force checkmate? In @SmallChess's answer, GM Samuel seem have made many mistakes...

http://www.chessgames.com/perl/chessgame?gid=1937249

Endgame where two knights against a lone king is a draw, you can't force a checkmate. However, with a pawn the side with the two knights can setup a mating net without running into stalemate. That's why it's always important to leave a pawn.

Just a few days ago, Karjakin demonstrated the technique against a very strong US grandmaster. Please note in the final position, it's a stalemate without the black pawn. Please go through the game, note how Karjakin never attempted to win the final pawn.

White is threatening Nh6, Nf7#. Again, this setup is impossible without the black pawn.

  http://www.chessgames.com/perl/chessgame?gid=1937249


Relation between checkers and chess After watching GM Vasyl Ivanchuk's victory against GM Baadur Jobava in checkers, I have a question in my mind:
Is it possible to relate checkers with the tactical knowledge of chess? If so, how?

While tactical skills (calculating accurately several moves ahead) can definitely translate, everything else is completely different


Where is the neural network used in MCTS? Where does an engine (such as AlphaZero) use its neural network in MCTS? It shouldn't be needed to evaluate positions reached via MCTS, since I'm under the impression that only terminal game states are evaluated (checkmate or draws). Is the neural network used in the expansion portion of the MCTS algorithm? I.e., choosing which new move to expand on a leaf node, rather than randomly choosing a new move? If that's the case then it doesn't seem like the neural network plays such an important role.

Neither AlphaZero, nor Lc0 (an open source project based on the AlphaZero paper), use MCTS in its pure form, because they do not perform game rollouts - the search is simply called MCTS because the way that it expands its tree is similar to MCTS.

Here are the main differences:

MCTS performs random rollouts to a termination condition (e.g. win, draw, loss) at leaf nodes to estimate to value of that node, whereas AlphaZero and Lc0 simply use the neural network to estimate the win value. They do not perform rollouts.
MCTS uses UCT to decide which node should be expanded. AlphaZero and Lc0 use the output of the neural network as an additional parameter in their versions of UCT: the neural network generates a probability associated with every possible move in the position, which allows the neural network to control the expansion of the search tree to some degree.

Lc0


What is the best way to prepare and optimize my skills for an Open section of a State tournament? I am an intermediate chess player (1500-1600 skill level USCF) and will enter the Open section of a State tournament. I would like to prepare for this tournament in three months, what would be the best way to become a stronger chess player to at least survive against 2000 USCF rated players or higher?

I think this question is a bit too broad to answer, but I'll give it a shot anyway. I think the best thing you can do in 3 months is to play as much as you can. You can play online and pick a semi-serious time control such as G/15. For all the games you lose (or really all of your games), you should analyze it thoroughly until you understand what it is that you could have done better. You can use a chess engine to help you as well as any other resource (Analyze the games with a high rated friend afterwards). If you played a poor move in an opening, you need to make sure you revise your repertoire. If you made a tactical blunder you need to ask yourself why you made that mistake and how you can avoid it next time, if you lost in an endgame maybe research that endgame to see how you can play better next time. I would suggest, at least, 5 games a day if you can manage.

There's not much you can do in 3 months, but the best thing you can do is play as much as you can and learn as much as you can from your losses. It is easy to lose and simply play another game and forget it happened. It is better to figure out why you lost and try to figure out how to avoid it next time.

If you could average 5 games a day, that's 450 games in 3 months. If you've learned anything from each of these games, that's got to be worth something.


Chess challenge #8: British knockout championship The British Knockout championship is taking place now as a warm-up to the London Chess Classic that starts this Friday. There have been very interesting games (especially the ones played by Nicholas Pert) like this one between Jonathan Rowson and Gawain Jones.

[fen "5rk1/4R3/1pQp4/3Pp3/4B1pp/4q1P1/PP3rPK/3R4 w - - 0 1"]

Gawain had a huge advantage but has just played ...h4 letting it slip away. Rowson has one chance to avoid losing the game. What should he play?

The tags seem to give a big hint . . .

   1 Rg7+! Kxg7 (Kh8 can't be better, since White can at least repeat with 2 Rh7+ Kg8 3 Rg7+)
 2 Qd7+ Rf1-f7 (Rf8-f7 3 Qxg4+ and perpetual check since White has access also to c8; K-moves get mated: Kf6? 3 Qe6+ and 4 Qg6, or Kh6/g8/h8? 3 Qh7+)
 3 Qxg4+ Kh8 4 Qxh4+ Kg8 and White can either take the perpetual starting 5 Qg4+ (checks from h3/g4/e6/c8) or go for more with 5 Rf1!?


Is there a way to automatically download KnightVision games from a chess blog? Taking as an example, this blog: http://wellingtonchess2012.blogspot.com/.

I can download the games manually by going to each game, clicking on "KVChess V2.31" in the bottom left corner, which then directs me to a link like this, after which I can copy-paste the PGN. However, it's very tedious to need do this game by game.

Is there some automatic way to accomplish the same goal of extracting the games?

you can do it in next way: open browser console (I tested it under google Chrome) and past next line:

document.getElementsByName("flashvars")

Then press Enter and you'll see something like this:

[<param name="flashvars" value="orientation=H&tabmode=false&light=f4f4fF&dark=0072b9&bordertext=494949&headerforeground=ffffff&mtforeground=000000&mtvariations=FF0000&mtmainline=000000&mtbackground=ffffff&pgndata=[Event "Club championship 2014"] [Site "Wellington Chess Club"] [Date "2014.12.11"] [Round "?"] [White "Michael Sole"] [Black "Aran Mol"] [Result "0-1"]  1. e4 Nc6 2. Nf3 d5 3. exd5 Qxd5 4. Nc3 Qa5 5. d4 Bg4 6. Bb5 O-O-O 7. Bxc6 bxc6 8. O-O Qh5 9. h3 Bxf3 10. Qxf3 Qxf3 11. gxf3 Nf6 12. Be3 a6 13. Ne4 e6 14. c4 h6 15. Rac1 Nd7 16. c5 f5 17. Nc3 g5 18. Rfe1 Bg7 19. Rcd1 e5 20. Ne2 f4 21. Bc1 exd4 22. Nxd4 Bxd4 23. Rxd4 Nxc5 24. Rc4 Nd3 25. Re6 Rhe8 26. Rexc6 Re1%2B 27. Kg2 Rd7 28. Rc2 Nb4 29. Bd2 Nxc2 30. Bxe1 Nxe1%2B 31. Kf1 Kb7 32. Rxh6 Nxf3 33. Rh5 Nd2%2B 34. Ke2 Ne4 35. Kf3 Re7 36. h4 Nd2%2B 37. Kg4 gxh4 38. Rxh4 f3 39. Kg3 c5 40. Rh6 Re1 41. Kf4 Re2 42. Rd6 Rxf2 43. Kf5 Re2 44. Rd3 f2 0-1">, <param name="flashvars" value="orientation=H&tabmode=false&light=f4f4fF&dark=0072b9&bordertext=494949&headerforeground=ffffff&mtforeground=000000&mtvariations=FF0000&mtmainline=000000&mtbackground=ffffff&pgndata=[Event "?"] [Site "?"] [Date "2014.12.12"] [Round "?"] [White "Croad, Nic"] [Black "Nijman, Brian"] [Result "0-1"]  1. d4 e6 2. Nf3 b6 3. g3 Bb7 4. Bg2 c5 5. O-O Nf6 6. c4 cxd4 7. Qxd4 Bc5 8. Qf4 h6 9. Nc3 Nc6 10. b3 Ne7 11. Bb2 Ng6 12. Qd2 O-O 13. Rad1 Qe7 14. Qc1 Rac8 15. Na4 d5 (15... Bc6 { is safer} ) 16. Nxc5 bxc5 17. Rfe1 Rfd8 18. Ne5 Nxe5 19. Bxe5 Ne8 20. e3 dxc4 21. Bxb7 Qxb7 22. Qxc4 Rd5 23. Rxd5 exd5 24. Qg4 Rc6 25. Rd1 Re6 26. Bc3 Nf6 27. Qf5 (27. Bxf6 Rxf6 28. Qh5 Rd6 29. e4 g5 30. h4 d4 31. hxg5 Qxe4 32. gxh6 Rg6 33. h7%2B Kh8 34. Qxc5 Rxg3%2B 35. fxg3 Qe3%2B 36. Kg2 Qe2%2B 37. Kh3 Qxd1 38. Qf8%2B Kxh7 39. Qxf7%2B Kh8 $10) 27... d4 $2 {[right idea, wrong move order. It was better to play g7-g6 first]}  (27... g6 $1 28. Qd3 Ne4 29. Bb2 (29. Ba1 Kf8 $5 30. h4 Ra6 31. Qc2 g5 $5 32. f3 Qc7 33. fxe4 Qxg3%2B 34. Qg2 Qxe3%2B 35. Qf2 Qxf2%2B 36. Kxf2 dxe4 { unclear} ) 29... d4 30. exd4 c4 $1 31. Qc2 (31. Qxc4 $6 Nd2 32. Rxd2 Re1%2B 33. Qf1 Rxf1%2B 34. Kxf1 Qh1%2B 35. Ke2 Qe4%2B $10)  31... cxb3 32. axb3 (32. Qxb3 $4 Rb6) 32... Qd5 33. Bc1 a5 34. Qd3 (34. Bxh6 g5 35. Qc8%2B Kh7 36. Bf8 Qxb3) 34... Nd6 { and it is hard for White to make progress} ) 28. exd4 g6 29. Qf4 (29. Qc2 $16)  (29. Qd3 Rd6 30. Qe3 Kh7 31. d5 Rxd5 32. Rxd5 Nxd5 33. Qxc5 Nxc3 34. Qxc3) 29... Ne4 $6 (29... Qd5 { [White is only somewhat better]} ) 30. Bb2 $4 (30. Qf3 $1 Rf6 $4 31. dxc5 $3 Rxf3 32. Rd8%2B Kh7 33. Rh8#) 30... Ng5 31. dxc5 (31. d5 Nh3%2B 32. Kf1 Nxf4 33. dxe6 Nxe6)  31... Nh3%2B 32. Kf1 Qh1# 0-1">, <param name="flashvars" value="orientation=H&tabmode=false&light=f4f4fF&dark=0072b9&bordertext=494949&headerforeground=ffffff&mtforeground=000000&mtvariations=FF0000&mtmainline=000000&mtbackground=ffffff&pgndata=[Event "WCC"] [Site "WCC"] [Date "2014.11.29"] [Round "10"] [White "Nick Barr"] [Black "Michael Sole"] [Result "0-1"]  { I was playing Nick Barr and he played the Queen’s gambit. I was expecting this since this is what happened last game. The game finished at 11:45 and closely matched our last game. } 1. d4 d5 2. c4 e6 3. Nc3 Nf6 { Queen’s gambit declined main-line} 4. cxd5 exd5 { Exchange line} 5. Bg5 Nbd7 6. e3 Be7 7. Bd3 O-O 8. Qc2 h6 {First non-book move.    } 9. Bh4 b6 {This move helps prepare for c5 and Bb7. } 10. Nf3 c5 {This move challenges White’s centre. } 11. dxc5 Nxc5 {This is a nice outpost for the Knight. } 12. Be2 $6 {I feel that this move is not needed as the Bishop pair is not doing much here and that a developing move would be better. This move also gives up some pressure on the e4 square.      } (12. Rd1) 12... Bb7 { Putting more pressure on e4} 13. Nd4 { This is a nice place for his Knight and stays here for some time} 13... Rc8 { Grabbing the c file} 14. Qd1 $6 { Again I feel that this move is not needed as the Knight was protected by the b-pawn. This move could have been spent on castling }  (14. O-O) 14... Nfe4 {Getting a nice place for my knight and threatening NxNc3 and then after the recapture, Ne4 wins the c-pawn. The bishop is also under attack.  } 15. Bxe7 Qxe7 {I like this position for Black } 16. Rc1 {Stopping the loss of the c-pawn } 16... Nxc3 17. Rxc3 Ne4 {This gains the c-file for Black } 18. Rb3 {I thought about this move for around 10 minutes here deciding between Qg5 and Rc5} 18... Rc5 {I picked this move to wait for White to castle before moving the Queen as it is in a nice place to attack the Queenside   }  19. O-O Rfc8 {Further marking the c-file } 20. f3 $5 { This is the type of move I was waiting for as this weakens his king side and gives me a target to attack.} 20... Nd6 21. Ra3 { Attacking the a-pawn} 21... a6 {Setting a trap. }  22. Qd3 { This move gives me the very useful c4 square for my Knight}  (22. Bxa6 Bxa6 23. Rxa6 Qxe3%2B 24. Kh1 Rc1) 22... Nc4 23. Rb3 Re8 { Putting pressure on e3} 24. Nf5 $2 Qe6 $6 {This is not the best move to win the pawn Qf6 is better. }  (24... Qf6) 25. Kf2 $2 {This move does little to protect the pawn } 25... Bc8 { Attacking the Knight} 26. Nd4 $2 { This move loses the pawn.} 26... Qf6 27. Qd1 $2 { Losing more protection} 27... Qh4%2B 28. Kg1 {Losing the exchange} 28... Nxe3 29. Qe1 $4 { This loses the Knight} 29... Qxd4 30. Qf2 Nf5 $2 { While this move is winning Rc2 is better} 31. Rxb6 $4 { Re2 is fatal now} 31... Qxf2%2B $2 { Not taking the bishop}  (31... Rxe2) 32. Kxf2 $2 { giving the Bishop back} 32... Rc2 33. Re1 Nd4 34. Rb8 Rexe2%2B 35. Rxe2 Rxe2%2B 36. Kg3 { } 36... Re8 {Winning for Black } 37. b4 Nb5 38. a4 Nc3 39. b5 Bd7 40. Rb7 Bxb5 41. axb5 axb5 {Getting rid of the pawns} 42. Rb6 Rc8 43. Kf2 Re8 44. g4 Kf8 45. h4 Re2%2B 46. Kg3 Ke7 47. g5 hxg5 48. hxg5 Kd7 49. Kg4 Kc7 50. Ra6 Kd7 51. Kf5 g6%2B 52. Kf6 {I played the risky move of Re6%2B giving white promotion chances} 52... Re6%2B 53. Rxe6 fxe6 54. Kxg6 Ke7 $2 {I played this thinking that white would play Ka6 so my king could keep up} 55. Kh7 $1 { This move makes promotion a sure thing} 55... b4 56. g6 b3 57. g7 b2 58. g8=Q {He promotes first but I promote with check } 58... b1=Q%2B {Now I can swap Queens and queen my other pawns } 59. Qg6 { If the king moves then I can still swap}  (59. Kh6 Qh1%2B 60. Kg7 Qg1%2B) 59... Qxg6%2B 60. Kxg6 d4 61. f4 d3 62. f5 exf5 63. Kxf5 d2 { Black resigned here.} 0-1">

You can easy copy this. If you need you can make some performance on this text as well. If you need more help just let me know.


If a pawn promotes to a checking piece while also revealing a check, it is a double check? I'm writing a chess engine just for fun, and during the validation of movement generation, I found some positions in Perft Results that differ from what my engine is producing.

As an example, take the below position.

[FEN "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 1"]

I found in the Chess programming wiki, the number of possible positions in depth 5 is 193690690, and my program matches this value.

However, regarding the number of possible double checks, my program found 8 more positions. The Perft Results from the Wiki indicate a total of 2637, while I found 2645.

I don't know what to think. Maybe the Perft Result from the Wiki does not consider positions where a pawn promotes with check whilst revealing a check, aka a discovered check. But there are only 6 moves where a pawn promotion results in a double check (3 positions, where the pawn may promote to queen or rook). Are the positions from Wiki wrong?

If someone wants to look at the positions, they can be found here on Google Drive.

Yes, a double check is when two pieces give check at the same time. It doesn't matter how you got to that position. As to whether there's an error on that wiki, it's probably best to try to ask its author. Maybe they can provide the full list of positions for you to compare.

I can think of two ways of giving double check while promoting. One is where you have say the black king in front of the white pawn, and a white queen or rook behind the pawn, and the pawn promotes with a capture, ending up as a new white queen or rook next to the black king. The other is where say the black king is on the seventh rank, white has a rook or queen on the other side of the pawn, and White promotes to a knight, queen or bishop giving check.


Formal rules for two-player bughouse without a clock I would like to know what are the formal rules for two-player bughouse without a clock. I'd like to think of each team as a single player.
It seems to me that bughouse chess works primarily because of the time limit imposed by the clock. If one should remove the clock, then it is easy to imagine a position where both teams are at a disadvantage to move first. Perhaps it is one team's turn to move on board 1 and the other team's turn on board 2, but whoever moves first will be put at a disadvantage on the other board because of a resulting capture. In such a case, neither player wants to go first, and the game enters a deadlock, with no team specifically to blame for not having moved.
Are there formal rule sets for bughouse chess that eliminate the possibility of such a deadlock?
I suppose that if one insists that play proceeds on each board in turn (white on board 1, black on board 2, white on board 2, black on board 1, repeat), then it would resolve this issue, since it would at any stage be a certain player's obligation to move, just as in any game. But in practice, bughouse chess does not obey such a convention, and I wonder whether there is a way to set up the rules to more closely follow the practice, but while avoiding the problematic kind of deadlock where neither team wants to move, but nobody is obliged to move.

In bughouse there are no formal rules, since bughouse isn't exactly a formal game :)

But from my experience, the two most common ways to deal with this are:

A player counts to 10 after moving, and his opponent has to move before he reaches 10.
You are only obligated to move once the person sitting diagonally from you (your opponent's partner) moves.

Other than these, I don't know of any other effective rules that would work.  I've played with some very strong bughouse players (borderline professionals), and even they often just resort to counting :)


Ideas behind the 8.Bd3 line in the 4.Ng5 Two Knights Defense In the Two Knights Defense, after

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.Bb5+ c6 7.dxc6 bxc6

8. Bd3 has become fashionable recently, and is considered a serious way for White to play for a win.

Yet, is seems an artificial move, going against basic opening principles, in particular blocking the d-Pawn. What are the main points of this line, especially in comparison to the "old" 8. Be2 move, and are there any typical traps or pitfalls to be aware of?

I think the main reason behind Bd3 is to provide a "safe" retreat for the knight and keeps to e-file open.  Both Nf3 and Nh3 have liabilities. A retreat to e4 also allow a further lose of time from f5, but this may be offset by black's LSB having less mobility.  The other option is Bf1, which while playable, also goes against basic opening principles.

Although this may apply here, paraphrasing Alekhine, to punish unconventional moves (Na5) you may have to play unconventional moves.


Moving a pawn to attack a piece on the 5th or 4th rank I have not been able to tell why my computer sometimes tell me that advancing a pawn from its original square in order to kick an opponent piece is right and other times wrong.
Take for instance, this game whose link is in case someone needs it: https://lichess.org/JdqqGV0Aekw4

In this case it is Ok to play a6 to kick out the knight.
However, in this position: I played the obvious Nf3.
 However, it seems that kicking out the bishop with a3 would be a great mistake.
I feel that sometimes kicking out these annoying pieces gets me in a less superior position whereas other times it is best kicking them out before castling or proceeding with the development of pieces and that is something that really confuses me.
I would appreciate if someone could really give some kind of rule of thumb or at least some things to consider before doing those pawns advances.

In the second example, after a2-a3, black does not have to retreat his dark squared bishop but can instead play ...Qxd4 when after axb4 Black can follow up with Qxd3.


What are the normal non-symmetric black responses to 1. d4 I'm returning  to chess.  I used open as 1. d4 when white, but have switched to 1. e4 instead (I find it is more interesting).  When I played 1. d4, I constantly found myself transposing into a symmetrical development against my opponent - usually due to playing Queens Gambit, but also from other lines.

I'm looking for a general list of black responses to explore so I can avoid a symmetric position when my opponent plays 1. d4

By reference, when white plays 1. e4 - black can respond with strong moves that force the white player into very non-symmetrical development (Sicilian or Caro-Kann).

I used to play a very positional set of openings, but am currently leaning towards openings that favor tempo and greater tactical possibilities.  I play mostly correspondence or slow over the board matches.  I don't want to rely on openings that rely on tricks and traps my opponent might miss.

There are a number of Black openings you can play in response to White playing 1. d4 (I'm assuming this is what you mean by "Queenside opening").

Here is a good list of Black openings against d4 you can look up that avoid symmetrical positions and promise good tactical play:

King's Indian Defence (1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6)
Benoni Defense (my opening: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6)
Albin Counter-Gambit (1. d4 d5 2. c4 e5!? 3. dxe5 d4)
Dutch Defence - Leningrad variation (1. d4 f5 2. c4 Nf6 3. g3 g6 4. Bg2 Bg7 5. Nf3 0-0)

There are many more, but I would recommend looking at one of these, based on what you've told me.  If you're looking for something where you're on the offensive immediately and there isn't too much theory to memorize, I would go with the Albin Counter-Gambit.

To look up an opening, I would recommend going to chess.com and finding a forum or article where the opening is discussed.  Then, I would recommend looking up some games online of strong Grandmasters playing the opening (just type into Google:  Albin Counter-Gambit Grandmaster games).

If you like the opening, the next step would be to buy a book on it - the Everyman books are relatively simple.


Do you find websites like chesstempo useful for improving tactical skills? I've been using chesstempo for quite a while solving lots of problems per day. What I noticed is that I don't feel that my tactical skills were improving. My results in tournament games were not improving either.

However chesstempo's estimate of my rating is more or less accurate (around 1950).

So the question is - did such websites help you to improve your tactic skills? if so, how many positions/hours per day were you solving? Did they provide accurate estimation of your rating (comparing to your real-life rating)?

I have not played enough or practiced enough on ChessTempo to really notice a difference in my tactical ability, but I am probably certain that if you spend enough time and I am not sure how long this is (it varies for each person) that your tactical skill will improve over time.  I also never paid attention to my rating on ChessTempo as I do not know what my actual rating is.

One thing I am certain of is that ChessTempo and other similar websites or puzzles in books will teach you to stop and think before making a move no matter what or will teach you to look for a tactic — whereas before, I would make the first move I saw without thinking.

In the end, it probably does improve your tactical skills, you just have to be patient and not assume that your tactical skills are not improving by the number of games you win or lose.  We often grade ourselves on whether we win or lose and I believe this is a big NO-NO. Especially if we lose, we often assume that we have not improved tactically, strategically, etc.


Exploiting wrong deviations from theory in chess openings What are some good sources about exploiting wrong deviations from standard chess theory during the opening? That is, given the fact that the opponent steps out of the canonical openings, and is not innovating a variant with style and making it stronger.

I would recommend the Chessok Opening Tree.

You can browse the lines you are interested in and see which moves have already been played (which at the beginning of an opening is almost every halfway sensible move). And most importantly you'll get an engine evaluation for each move, which immediately tells you which of these halfway sensible moves is a blunder.

If you are further down the rabbit hole and the line has never been played before, of course you have to rely on your own chess understanding to come up with the most likely human moves and can then use an engine to find out how to punish them. Online, this would be possible on Chess24, though as non premium member you might have to wait a while for the engine evaluation to come up.


Exact definition of a blocked pawn What exactly is a blocked pawn? Is it a pawn with any of the opponent pieces in front or does it have to be an opponent pawn? Will the pawn be considered blocked if it can capture?

Add any other criteria that defines a blocked pawn.

A "blocked pawn" is a rather general term that describes a pawn that cannot advance. It can be blockaded by either an opponent's piece or pawn, and in certain rare cases it can be blocked by a fellow pawn (i.e. doubled pawns). However, perhaps the most common example of a blocked pawn is one that is isolated. Here is an example of a typical IQP position: (isolated queen pawn)

r4rk1/pb2bppp/1p1qpn2/3n2B1/3P4/P1NB1N2/1P3PPP/R2QR1K1 w - - 0 1

It is a well known positional idea to blockade the opponent's passed pawn. The reason why the square in front of an isolated pawn is commonly used as an outpost is because the d-pawn does not have a fellow e or c pawn to kick the knight out of the d5 square. Therefore, Black's plan is to blockade the pawn, exchange off the minor pieces, and eventually win the pawn in the endgame. The following position illustrates this plan:

3r2k1/p2q1pp1/1p5p/3rp3/3P4/P2R4/1P1Q1PPP/3R2K1 w - - 0 1

Blockading your opponent's pawn is also a common idea in positions with a backward pawn:

2rq1rk1/1p3pp1/p1npbb1p/3Np3/4P3/1BP1NP2/PP1Q2PP/3RR2K w - - 0 1

Notice how the d6 pawn is blockaded by the knight on d5. Keep in mind that in positions with backwards pawns, the pawn itself is weak and the square in front of it is also begging to be occupied. A long-term plan could be perhaps to eventually win the d6 pawn.

In such, positional maneuvers are usually rooted in scenarios where the pawn is blockaded by a piece. To answer your last question, a pawn wouldn't be considered blocked if it can capture because it will have a square to go to. A blocked pawn by definition cannot move anywhere.

If you want to read more about blocked pawns and their importance in endgames, check out the Wikipedia article involving key squares and zugzwang.


Can watching grandmasters' games improve my chess 'thinking'? Can my chess "thinking" (positional, tactical, strategic thinking, etc.) improve by watching grandmasters' games regularly? Of course, this is in addition to regular games/tactics solving etc.

As an example, when learning any foreign language, it's a good practice to watch movies and listen to language as much as possible.

I'm interested in pattern matching, as my brain is very good at it. I think that by constantly watching high-quality games one can develop knowledge of the best moves/strategies/tactics.

Has anyone applied this technique or has an opinion on this? Cheers

Chess "thinking" is first and foremost a skill. As such it has to be practiced actively. Passively acquired knowledge will only flesh out what you already can do, it will not improve your chess all that much.

Of course if you try to follow all the variations of the commentators and constantly come up with variations on your own, you will benefit from watching games, thought the level of these games probably doesn't have much of an influence on the training effect.

Generally improvement happens outside your comfort zone. If it doesn't feel like you put something into it, you probably wont get anything out of it.


Morphy Defence in Ruy Lopez I don't get the point of Morphy's Defence in the Ruy Lopez opening:

  [FEN ""]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6

If White's purpose was to exchange Bishop for Knight and take the e5 pawn after it loses its defender (plus create some pawn weaknesses for Black), then the 3...a6 move comes too late to prevent it. Likewise I don't get White's retreat in all the variations that follow except for the exchange variation.

The basic idea of the opening was to snatch e5 pawn, but by playing Qd4 or Qg5 Black returns the pawn with good play.

This forced White to seek other ways of reaching advantage, so he tried with Bxc6 counting on a won pawn endgame. However, things are not so easy since Black has ample of compensation in his bishop pair-remember that bishops are good in open positions-and doubled pawns control a lot of important squares.

Since that try failed, White needed to try something else, and the only option left is bishop retreat. If they play Bc4 Black can transpose into Italian game with the extra temp since a6 has been played. Since a6 is an important move in those lines for Black, he would gain a small plus from the bishop retreat. That leaves Ba4.

With this retreat White keeps pressure on e5 pawn and hopes to force Black into making some concession. Black will do his best to develop and defend without weakening himself but in the end he fails to do so. He must play b5 at some point to release the pressure from the White light-squared bishop. After b5 Black will have  compromised pawn structure on the queen side ( backward c pawn and exposed b5 pawn ) and that is the concession White hoped for.

It isn't much-Black is still OK-but it will guarantee White a long initiative-which is better overall result than what other lines offer.

The reason for this being Black's c-pawn is blocked by a knight so he can't participate in the battle for the center. This enables White to seize initiative in the center by forming d4+e4 pawn center supported with the c3 pawn. Black will lose time to reorganize his queen side in order to counterstrike which gives White time to meet comfortably Black's plan. This usually involves Nbd2-Nf1-Ne3/Ng3 maneuver, preparing king side attack, but can be a4 thrust, or simply a favorable change of the pawn center's type-he can block the position with d5 or open it with an exchange like dxe5 or dxc5.

The last option is the most dangerous for Black so he needs to play very passively for a while before he counter-strikes.

In this Wikipedia link you can see the list of variations. Notice that in the main line there is one thing in common for all the Black's responses-they regroup their queen side to meet White's initiative.

To conclude:

By retreating the bishop to a4 White gains small concession from Black in view of compromised pawn structure which results in White's better control of the center, which results in small but lasting initiative.

Hopefully this answer sheds some light for you.

If you have further questions leave a comment.

Best regards.


What insights have neural networks revealed about chess? I've been interested to see an analysis of the decision making processes of an NN in determining the difference between good and bad moves. The only writings I've seen is about how NN can be applied to other fields. I've heard that grandmasters are using NNs to train for tournaments.
Can anyone point me to such sources relating to this particular query?

I think NN's brought us 3 main types of knowledge about chess: Specific good types of positions, that playing positionally is viable at a high level, and that we are nowhere near creating a perfect chess engine.

Fawn pawns (6th rank pawns that are safely nested in opponent pawns) are the clearest example here. Another example would be the strength of a pair of opposite color bishops which most AB engines underestimated.

AlphaZero/LC0 both play in a much more positional manner. While hard to quantify, this basically means playing to maximize space and mobility rather than pure material.

The fact that LC0 plays so differently than SF and is about at the same level means that neither are close to perfect play. The intuition here is that as you approach optimal strength, all strategies should converge, so the difference between play styles implies that there is a lot of ability for both to grow stronger.


Where can I find lists of best games per tournament? I would like to obtain a list of best games per tournament (World Chess Championships, Chess World Cup, ...).

By "best" I mean games that either have won a brilliancy prize, or games that are considered by some other participants in the tournament as a best/most beautiful game.

Chess Informant quarterly subscription gives you the best of games played in that quarter.

Or, The Week In Chess is the raw scores of games with no commentary and no qualifications.


Positional opening for Black I have recently (two months ago) become very interested in chess, after playing it for about 10 years at a club, spending time on it only one evening per week.
Previously, I did not think about my opening at all, and just played 1. e4 as White and 1. e4 e5 and 1. d4 d5 as Black. Currently, I play the English as White, using the wonderful books of Mihail Marin, and the Modern as Black, using a number of different books (Davies, Hillarp Persson and Lakdawala).

I am very much satisfied with the English, as it ensures a solid position, most opponents have to improvise their set-up at my level (~1500), and the books of Marin help me in having a comprehensive repertoire. After a game, I can look up who deviated first from theory, and remember it for later games.

However, it does not seem that there is such a book as Marin's for the Modern opening, and though my results with the Modern are good till now (two draws against 1650 average, and one win against 1200), I wonder if there are other solid openings which I could use as Black. Preferably, an opening for which there is a good book which explains the ideas and themes of the opening. Do you have any suggestions?

Positional opening for Black

If I were you I would stick with the English opening as White.

As for Black, let us start with reply to 1.d4. I would strongly encourage you to learn Queen's gambit declined, as it is immune to transpositional tricks. The resulting positions require both theoretical knowledge and knowledge of typical plans. Your other option is Nimzo-Indian defense, but White can rule it out with a clever move order. Still, you can steer the game back into Queen's Gambit declined, with resulting lines being beneficial for Black, or you can learn Queen's-Indian defense. Also, when playing White, after 1.c4 e6 2.e4 is toothless, but 2.d4 d5 transposes into Queen's gambit declined/Nimzo-Indian/Queen's Indian, so this would save you a lot of learning time by reducing the amount of material you need to cover.

As for reply to 1.e4 there is French defense, Caro-Kann, or Petroff defense ( but be prepared to learn a lot about King's gambit ). Again, when playing White, after 1.c4 c6 2.e4! you sidestep many popular openings like Grunfeld, Slav/Semi-Slav and so on, and you transpose into Caro-Kann so I would suggest getting a book on it. The beauty of this move order is that you can transpose into Panov-Botvinnik attack, which is positional and requires knowledge from Black, else he may end up in a lost game, while you may play more or less on general principles. Either way, Black must invest more work here, as this line is critical for both sides. French defense may work too, as it is very solid, but you will still need to handle 1.c4 c6 and if you do not want to transpose into Caro-Kann be prepared to play against Slav or Semi-Slav.

  I wonder if there are other solid openings which I could use as Black. Preferably, an opening for which there is a good book which explains the ideas and themes of the opening. Do you have any suggestions?

For French defense I find the book Nikita Vitiugov-The Complete French A Complete Black Repertoire quite useful.

For general ideas in Caro-Kann you can use Joe Gallagher-Starting Out The Caro-Kann and Petter Wells-Grandmaster Secrets The Caro-Kann and Karpov & Podgaets-Caro-Kann defense Panov Attack for Panov-Botvinnik Attack. For opening moves you have the Lars Schandorff-Grandmaster Repertoire 7 The Caro-Kann. These are more than enough to get you going.

For Nimzo-Indian and Queen's Indian defense you will have to find books yourself, since I do not play those defenses, and since there are so many books on those I do not wish to recommend bad ones.

As for Queen's Gambit Declined, you can start with Mathew Sadler-Queen's Gambit Declined since it covers typical plans for both sides very well. As for opening moves there are many books, seek on Amazon and you will find them. Unfortunately you will need most of them, in order to have your repertoire complete, and still it might not be enough. Take care especially for Alatortsev variation as it is very useful for Black if played right. Unfortunately I haven't found a good coverage on this line, and I must warn you that some novelties have been introduced from a year or two ago. I was lucky to find them, but God knows how many novelties I have missed.

That is it from me for now, if you have further questions leave a comment.

Best regards.


If there is a winning strategy, is it for White? We do not know, given two perfect players White and Black, whether the game would necessarily end in a draw, or necessarily end in a win (for either Black or White).

However, can we prove that if there is a winning strategy, then it is for White? In other words, can we prove that Black must either lose or draw?

If there is such a proof, no one has found it, and I doubt very much that such a proof exists (it is hard to imagine a mathematically provable "guaranteed-draw" strategy as White). One would certainly expect White to have an advantage if anybody did, but there are some downsides to going first as well (you have to disclose information before your opponent), so it is theoretically possible that the downsides outweigh the upsides. That said, the probability of that being the case seems to be infinitesimal.


Intermediate Chess Books Does anyone have any suggestions for intermediate chess books? Tactics or endgames would be the topic that I'd mainly like to focus on!

You cannot go wrong with the Yusupov and Aagaard series of books. Both are tremendous. Yusupov's books cover everything, and not in any order, so one day, you will get some tactics, endgames, and maybe even some opening stuff. They are very varied.

Yusupov was a top-10 player, multiple-time candidate, and considered one of the greatest trainers living today.

You might also like Quality Chess' "The Woodpecker Method", which is an immersion course in tactics.

You can find them here.

New in Chess also has a lot of books aimed at the intermediate market:

Improve Your Chess Pattern Recognition
Train Your Chess Pattern Recognition
Strategic Chess Excercises
Complete Manual of Positional Chess volumes 1 and 2.

Some of these are not tactics, but they are still problems that are designed to have you analyze.


Is there a specific penalty for intentionally damaging chess pieces or the board? If a player intentionally damages a chess set (e.g. breaks a piece in two, cracks the board, etc.), is there a specific penalty under FIDE rules? I'm not talking about moving pieces around surreptitiously or attempting to obscure the current game state, but something like a player getting angry and, while lawfully moving their knight, they bite it with their teeth, drool on it, or crack it with their hands before putting it back down.

It seems like it might fall under Rule 11.1, which provides

  11.1 The players shall take no action that will bring the game of chess into disrepute.

According to 11.6, such a violation "shall lead to penalties in accordance with Article 12.9."

Would such an act fall under this general rule of sportsmanship, or is there a specific penalty (or specifically no penalty at all) for this?

First of all I would consider the Preface:

  The Laws of Chess cannot cover all possible situations that may arise
  during a game, nor can they regulate all administrative questions.
  Where cases are not precisely regulated by an Article of the Laws, it
  should be possible to reach a correct decision by studying analogous
  situations which are regulated in the Laws.

I think it should be obvious that the sort of behavior you describe is wrong even if there is no rule that explicitly says "biting, drooling on, or cracking pieces is not allowed". :-)

But you can also consider

  11.5. It is forbidden to distract or annoy the opponent in any manner whatsoever [...]

I don't think any arbiter would question your claim of being annoyed if your opponent is chewing on the pieces!


ELO rating and experience I was looking at many players' ELO over time graphs and noticed something interesting. Usually players stay in the same 200-300 bracket through very long periods of time (I'm talking decades here) despite staying active and playing. My intuition would be that experience would have some positive correlation with ELO but it looks like it's not the case. I know many research has been done on this topic but I have never seen this question explored.
To recap: Is there a known positive correlation between experience (games played) and ELO improvement? If there is no such correlation (as I found to be the case through my limited observation), what are the possible explanations?

If you are asking why players don't improve despite decades of playing the simple answer is that the more time you spend practicing and reinforcing your mistakes the more ingrained they become and the more likely it becomes that your level will hardly change..

The principle teaching of the Soviet School of chess as described by Dvoretsky and others is that the key to improvement lies in annotating your own games.

Only by critically examining the (bad) moves you make can you identify the kind of mistakes you typically make and only then can you take positive steps to correct them.

This is a very active thing to do. It involves putting your brain into gear. Just putting your game into an engine and seeing where the evaluation changes by a big margin and noting the engine suggestion doesn't count. That is just passive.

EDIT: Analyzing and annotating your own games to identify mistakes with the idea of avoiding those mistakes in the future, something the Soviets practiced in the Botvinnik era, is also one of the centerpieces of Axel Smith's award-winning 2013 book, "Pump up your Rating".

Here is his summary of this technique -

1) Analyse your games with a friend; avoid using an analysis engine
2) Annotate the game in ChessBase, and highlight your mistakes
3) Check the analysis with an engine, and update the annotations
4) Write down the mistakes in a text file
5) Collect all the mistakes in a List of Mistakes, where they are sorted into various categories
6) Make conclusions about typical mistakes, and how they should be avoided in the future

Axel Smith also gives examples of some of his own mistakes and how he used this technique to identify them and correct them in his play.


I don't understand the central-control difference between 1. e4 and 1. e3 The books/articles tell me that the center is d4, d5, e4, and e5.

1. e4 controls d5, but 1. e3 controls d4.

Both control one square in the center, no?

Yet 1. e4 is apparently a vast improvement over 1. e3.

How would occupying e4 make a difference? Surely a pawn doesn't control the square it's on but rather the squares on which it can capture?

I really wish these books/articles aimed at amateurs would be more precisely formulated. There's just way too much frustrating handwaving. Surely I'm not the only amateur who's had this confusion.

There isn't that much difference in strength between having a pawn on e4 or one on e3 (usually accompanied by one on d4); there are pros and cons to both (and a pawn on e3 can still go to e4, but not the other way around). The difference is between putting them there on move 1.

Let's take a look at the effects of 1.e4 and 1.e3, concentrating on the actual position. For 1.e4:

1.e4 influences d5 and f5, squares on which black might want to place a pawn. 1.e4 d5 2.exd5 gives white chances for an advantage, and 1.e4 f5?? is basically impossible.
If you want to play an opening with a pawn on e4, now is the time to play it there. It's a pawn move to an undefended square, black can easily prevent it otherwise. Observe that the most common replies to 1.d4 are 1...Nf6, 1...d5 and 1...f5, all of which prevent 2.e4.
The bishop on f1 is opened up, and it might go to the nice square c4 (in case of 1.e4 e5 2.Bc4).

For 1.e3:

1.e3 influences d4 and f4, but so what? If white wants to put a pawn there he could already do so, and black can't even legally put anything on those squares next move. So that's not relevant right now.
There is no way in the next ten moves or so that black will be available to prevent a move like e2-e3; it can be postponed until the perfect moment.
White blocks the bishop on c1. Without knowing anything whatsoever about black's setup, white basically already rules out putting the bishop on e3, f4 or g5. If you're going to fianchetto it, why not just start 1.b3. You've just made a concession before black has even played a single move!
The bishop on f1 is opened up, but it can't do much. 1.e3 e5 2.Bc4 just runs into 2...d5 (not enough control over that square).

It's fine to play an opening that involves e3 (as long as you put one or two other pawns near the center instead, otherwise you won't control anything on his half, white is supposed to be attacking), but doing so on move 1 has no advantages. That's a big difference with a pawn on e4, which can be played there on move 1 "for free" and usually only with difficulty after that.


Why isn't the English Attack popular vs. the Sicilian Kan? As title above states, why isn't the "English Attack" popular vs. the Sicilian Kan? I mean the White setup in the Open Sicilian with Be3, Qd2, f3 and eventually g4 and h4. As far as I know, it is fairly popular vs. the Najdorf, the Scheveningen, the Classical, the Taimanov, and the Dragon (in which case it is named "Yugoslav Attack"). But vs. the Kan, almost nobody, at least at top level, plays it. Is there a specific reason for this fact, or it is just a matter of "fashion"?

The English attack is only true mainline for the d6 Sicilian. The reason behind this is that in the e6 Sicilian variation, it's a lot easier for black to pressure your center and break through with a quicker d5. Specifically, black can play a fast Bb4 (pinning your knight and therefore influencing the all important e4 and d5 squares), and break out with d5.

[FEN ""]
1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. Be3?! Nf6 6. Nc3 Bb4! 7. f3 O-O 8. Qd2 d5!

Even if black is worried about the pawn structure changing with white playing e4-e5 after d5, then he is fine too if he plays Qc7 instead of O-O to cover the e5 square. Regardless of the exact move order, as soon as black gets in the d5 break, then it's black who is slightly better out of the opening, not white. This English attack setup is too slow against the Kan. Instead of Be3 and a later f3, Bd3 is often used to defend the e4 point and avoid most of the sting out of the Bb4 pin.


Starting elo rating at chess.com I am confused about the starting elo rating of new members at chess.com.
Most of them start at 1200 but some of them have 800, 1000, 1400, 1600 or even 1800. How is it decided what is the initial value of the elo rating of a new member?

You can select your starting rating on the register page by changing the skill level options.

For example, if you select "expert" your starting ratings will be 1800 (at least when I tried it).

So, to answer your question, "How is it decided what is the initial value of the elo rating of a new member?", it is decided by what option the user chooses.


What is the proper etiquette in Team Chess Championships? In Team Chess Championships, what is the proper etiquette for being a player?

This question is mainly focused on:

Can I see my teammates’ games during the match? (I suspect I can.)
If I win quickly, can I go away, or should I stay?
If I leave the hall after winning, can I return?
Can I have contact with my teammates? If so, to what extent is this limited?
Can I call a friend, and let him play in the now empty board of my match, for opinions on the game just finished, or am I forced to do it outside? (This is assuming, of course, that we don’t talk loudly.)

Officially most of it depends on the team competition, it will have regulations. But I think these questions will have pretty much the same answers everywhere.

Yes, you're sitting right next to them, and you can walk around as usual, so you can see their boards.

Usually teams have a team leader also, whose role is to advise you about offering or accepting a draw (but not in a way that gives you information about his opinion of your own position! If you ask him "Can I offer a draw?", he must answer yes or no immediately; he can't walk up to your board, think for a while, then say no. It would be obvious then that he thought you had the better position, which is a big no-no). He can otherwise watch all games all the time though.

You can leave if you want. The team leader has to sign the result form at the end, but the players are done when their game is over. Most of the time you'll be eager to know the end result and stay, though.
Re-entering the hall really depends on the regulations. You'll be a spectator. In most amateur leagues, spectators can just stand next to the boards if they wish, so so can you.
Officially you can not speak to anybody during any chess game, including team matches. Practice is slightly less rigorous. If you discuss the ongoing chess games, you're definitely over the line.
No, of course you can't analyze a game right next to ongoing games, that's clearly distracting for the players. Usually there will be a separate room where games can be analyzed.


What I thought was winning tactic, apparently was mistake I was recently playing a game as black against the Ponziani when this position came up. (I recommend you flip all the boards to show from black's perspective)

Here's the beginning of the game:

[fen ""]
1.e4 e5 2.Nf3 Nc6 3.c3 d5 4.Qa4 Bd7 5.exd5 Nd4 6.Qd1 Nxf3+ 7.Qxf3 Nf6 8.h3 e4 9.Qe3 Bd6 10.d3 O-O 11.dxe4 Nxe4 12.Bd3 f5 13.Bxe4 fxe4 14.O-O Bf5 15.c4 Qf6 16.Nc3 Rae8 17.Bd2 Be5 18.Qg5

In the starting position, both sides are apparently equal (0.0)

[fen "4rrk1/ppp3pp/5q2/3PbbQ1/2P1p3/2N4P/PP1B1PP1/R4RK1 b - - 6 18"]

1... Qb6 2. Bf4 Bxf4 3. Qxf4 Bxh3

After 2.Bf4 black has apparently made a blunder, putting me 90 centipawns ahead. In the game, I spent 5 minutes debating between Qxb2, h6, and Bxf4 finally choosing the last, seeing it as the simplest most effective option.

Apparently, Bxh3 was a blunder on my part, putting white ahead 90 centipawns. (So this move helped white by 1.8) Only, I cannot understand why? I ended up winning the game with the following moves.

[fen "4rrk1/ppp3pp/1q6/3P4/2P1pQ2/2N4b/PP3PP1/R4RK1 w - - 0 21"]

1. Qg3 Bd7 2. b3 e3 3. fxe3 Rxf1 4. Rxf1 Rxe3 5. Qf2 Rxc3 6. Qxb6 axb6 7.Rf2 g6 8. Kh2 Bf5 9. Re2 Kf7 10. Rb2 Rc2 0-1

I feel like the decision to play Bxh3 was justified and what helped me win the game. Yet the engine disagrees. Could somebody tell me what the problem with Bxh3 was?

First of all, I don't think it is productive to call moves "blunders" when they're just not the best moves according to the computer. Chess is a game between humans. I like to reserve "blunder" for moves that are really terrible.

That said, after 20...Bxh3, Komodo 9.02 recommends 21.Qe3 for White, forcing Black to exchange queens, after which material is equal (remember that you were down a pawn to start with) and it likes White's position better.

It prefers to delay the discovered attack on the queen by playing 20...e3, threatening 21...Bd3 (winning an exchange), which is really hard for White to deal with. Komodo's line is 20...e3 21.fxe3 Bd3 22.Qxd4 Bxf1 23.Qxb6 axb6 24.Rxf1 Rxe3 and Black is up an exchange for a pawn.


King's Gambit, Fischer's Defence 6. Ng1. Wait, what? I'd like to play the king's gambit without getting into piece sacrifices, but Fischer's Defence is unsettling me.  This appears to be described as the "main line".

[FEN ""]
1.e4 e5 2.f4 exf4 3.Nf3 d6 4.d4 g5 5.h4 g4 6.Ng1 *

Attempting to be impartial, I look at the board as white after 6. Ng1 and think:

I'm white and I expect to be slightly better in the opening (which I would be if I choose a more mainstream opening).
I've given up a pawn (which black could probably hold onto with ...h5 and Bh6), so I expect compensation.
I played 2. f4 for the purpose of having the initiative.
I have a damaged kingside, and maybe black will completely demolish it with ...f3.
I have a nice pawn center.

My conclusion: while white does not seem losing, there has to be a better choice of openings for white.

Questions:  Is this position as bad as I think it is?  (Are there some subtitles I'm missing?)  Are there reasonable non-mainstream deviations from this line?

Your objective assessment of White's position after 6. Ng1 is quite on the mark.

A. Objectively speaking...

It's hard to see how this position could be good for White.

On the plus side -

White has a good center.
Black's pawn on f4 is weak.
Black's kingside is a bit loose.

On the minus side -

White is a pawn down at the moment.
White's own kingside is weak.

Is a good center worth a pawn? Sometimes it is, sometimes it is not. In this position, it can be shown that at best White is only equal. There is no line that gives White an advantage.

B. Subjectively speaking...

White played the King's Gambit because White wanted a sharp tactical game.

On the plus side -

The White player has successfully achieved a complex tactical position which suits his/her style of play.
Complex tactical positions may not suit the Black player's style of play. Perhaps he/she played 1...e5 with the intention of getting a quieter position.
If the White player is better at tactical positions than the Black player, White has greater chances of winning the game.
The White player may be better prepared in the opening than Black player for this particular line.

One example - Nigel Short, a master of tactical positions, outplayed his strong Grandmaster opponent Vladimir Akopian in this position, playing White.

On the minus side -

Complex tactical positions may suit the Black player's style of play and Black might enjoy these complications.
Black might be as good as White in tactical positions or even better. Thus, White has good chances of losing the game.
Black might be very good at defense and at best White will only manage a draw.
The Black player might be prepared just as well in the opening as the White player or even better in this particular line.

One example- the great champion of the King's Gambit and a master of tactics, Boris Spassky himself, played this position both with White and with Black, winning the game with Black.

It seems to me that White's reasons for going into this line are more subjective than objective. The computer evaluations all favor Black slightly, but that's expected because Black is materially a pawn ahead and computers often are biased towards material. Objectively speaking, here are some lines which show that White doesn't get anything special out of this opening. In my opinion, in the line after 6...f5!?, White is even slightly worse.

    [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
    [Event "6...f5!? and Black might be slightly better"]

    1. e4 e5 2. f4 exf4 3. Nf3 d6 4. d4 g5 5. h4 g4 6. Ng1 f5 (6... Bh6 7. Nc3 c6 (
    7... Nf6 8. Nge2 Nh5 9. g3 O-O 10. Bxf4 Nxf4 11. Nxf4=) 8. Nge2 Qf6 9. g3 f3
    10. Nf4 Qe7) 7. Nc3 fxe4 8. Bxf4 (8. Nxe4 Qe7 9. Qe2 Nc6 10. c3 Bf5 11. Nf2 Bh6=+
    ) 8... d5 9. Qd2 c6 10. Nge2 Nf6 11. O-O-O Be6 12. Kb1 (12. Ng3 Bd6) 12...
    Nbd7 13. Ng3 Bb4 14. a3 Ba5 15. Be2 Bc7 16. Rdf1 Bxf4 17. Rxf4 Qe7 18. Rhf1
    O-O-O=+

One sample Grandmaster game in this line -

Hector vs Peter Leko 0-1 1995

4. Bc4!? is a perfectly playable alternative to 4. d4. The point is that Black has to "waste" a move playing 4...h6 first and cannot play 4...g5 directly. If 4...g5, then White get's a better position after 5. h4! as follows -

    [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
    [Event "Black cannot play 4...g5 after 4. Bc4!?"]

    1. e4 e5 2. f4 exf4 3. Nf3 d6 4. Bc4 g5? 5. h4! g4 6. Ng5 Nh6 7. d4 Bg7 8. Bxf4+=

However, I should mention that after 4...h6 and 5...g5, Black is very solid in the mainline resulting position and it's not easy for White to break through.

    [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
    [Event "4. Bc4 h6!? 5.d4 g5 and Black is doing well"]

    1. e4 e5 2. f4 exf4 3. Nf3 d6 4. Bc4 h6 5. d4 g5 6. O-O Bg7 7. c3 Nc6

  Are there reasonable non-mainstream deviations from this line?

Considering the above discussion, I think a reasonable non-mainstream deviation would be to play 4. Bc4 and 5.h4!?, preventing g5. Objectively speaking, White is still slightly worse because of the material deficit, but subjectively speaking, the position is quite complicated with plenty to play for. One idea for White's would be to hold on to the strong pawn center, castle queen side and attempt to put pressure on Black's f4 pawn with moves like Ne2.

      [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
      [Event "5. h4!? is worth a try"]

      1. e4 e5 2. f4 exf4 3. Nf3 d6 4. Bc4 h6 5. h4 Nf6 6. Nc3 Nbd7 (6... Bg4 7. d4
      Nh5 8. Ne5! dxe5 9. Qxg4 Nf6 10. Qf5 Nc6 11. dxe5 Nd4 12. Qxf4 Nxc2+ 13. Ke2
      Nxa1 14. exf6 Qxf6 15. Nd5 Qxf4 16. Bxf4 O-O-O 17. Rxa1+/-) (6... c6 7. d4 b5
      8. Bd3 Nh5 9. Ne2) 7. d4 Nh5 8. Qd3


How would you play this position as White? [FEN "r1bq1rk1/2p1ppbp/p5p1/1p1n4/3PNB2/1P2PN2/n4PPP/2RQKB1R w K - 0 1"]

I'm not sure what move makes the most sense in this scenario. I would love to learn from others.

The elements which I notice are The strong knight on d5, the attacks on c1 and f4, the backward pawn on c7, and that white is down a pawn.
Since I can't do anything about the Nxf4 threat, which would ruin the pawn structure and create a weakness on d4, but also eliminates the powerful knight, my first candidate move would be Ra1 to try and regain the pawn due to the pin.  I'd have to consider the reply Nac3 followed by b4, which would sheild the c7 weakness, save the pawn, and the knight may prove to be strong on d3.
The second candidate is Rc5, Rc6 is bad due to Bb7, just to keep pressure on c7.  After Nxf4 and rerouting the other knight to d5, black just has a better game.
The third option is to sacrifice the rook and save the bishop by Bg3.  Being down 3 pawns worth of material and black protecting all of his weaknesses, white has no compensation.
With all considerations, I would choose Ra1 and, if black entrenches on c3, to go for an all out attack on the kingside while black's pieces are distracted on the queenside.  Due to white's lack of development and black's solid kingside, there is little chance of saving the game, but I believe that this is the best attempt.


How can I get a collection of chess games with a 'Greek gift' sacrifice? I would like to make a collection of chess games that feature the 'Greek gift' sacrifice. There are few games on chessgames.com annotated with this sacrifice. I could find blogs with individual examples of games with this type of sacrifice (example: 1, 2, 3, 4, 5, and 6); however they are not in a readily downloadable format.

Is there a collection of games that feature this sacrifice? If not, is there any way I can search for and get collections of games featuring this sacrifice using a chess database like SCID?

Something which might help here is Chess Query Language. Just like SQL does for relational databases, CQL can search in a database of chess games for positions/games which match certain criteria.

I must say I have never used it myself, but it seems to be capable of amazing things, far more complex than what you're looking for. Here is an old article showing a few beautiful studies Tim Krabbé was able to find with the help of CQL.


How can I open (or convert into .PGN) old Chessmaster .CMG files, without Chessmaster? I have many old chess games saved from Chessmaster 7000, 8000, and maybe even 9000. They are all saved in the Chessmaster .CMG file format.

How can I access these games today?

I would like to either open them or convert them to .PGN format.

To access them today, you either need to reverse engineer the format (hard) or export them to PGN inside Chessmaster (moderate):

  HOW TO CONVERT CHESSMASTER GAME FILES (*.CMG) TO *.PGN FILES

  (*.CMG files or Chessmaster game files are typically for use with the
  Chessmaster programs and may contain various enhancements, such as
  annotations, illustrated voice analyses, etc. Cf. page 25 of the
  Chessmaster 9000 user manual.)

  Log in (on Chessmaster 9000) and go to Game Room.
  Click on "File" in upper menu bar and then on "Load" in pull- down menu, to get "File Open" window.
  By default, the "Look in" box will show a folder that is named the same as the name you log in with. Let's say it is "Loginame." If the
  file you wish to convert is not in the list in the big box below, then
  you will have to find it by scrolling to other folders. In front of
  the file the little icon will contain the number 9000. (The icons for
  *.PGN files contain the initials PGN.)
  Click on the name of the *.CMG file that you wish to convert. The name will show in the "File name" box below. The "File of type" box
  should mention Chessmaster files. Leave "Auto" in the last ("Open as")
  box. Click the "Load" button and get the game on the board.
  Click on "File" and then on "Save" in the pull-down menu.
  "File Save" window comes up next. Check that the "Save in" folder is acceptable. (Your "Loginame" folder is OK, but you could even
  scroll to save the file on the floppy in drive a:) In the "File name"
  box below you can fill in a shorter (8-character) name of your choice,
  rather than accepting the long name created by Windows. In the "Save
  as type" box at the bottom,scroll and pick "PGN Game Files (*.PGN).
  Click on the "Save" button. In the "Annotation Type" window that comes
  up next, accept "None" by clicking "OK."
  The *.CMG file has been stripped to the plain *.PGN format and saved in the folder that you have chosen. If you wish to add this file
  to a database of your choice, see our earlier instructions under the
  appropriate heading.

Obviously, if you don't have Chessmaster installed, you will need to do that.  Easiest way might be to install a Windows VM, then install a legacy copy of Chessmaster.


What's the name of this pieces' design? Please can anyone help me to find the name of this chess pieces' design?

The shape of the pieces is a standard Staunton chess set. However, the marbled material makes it look rather unusual. I am not up on the rules about color use, but I have my doubts that it would be permitted in tournament use if one of the players objected.


How much should I rely on an external board or diagram when reading a chess book? I'm currently making my first serious attempt to read a chess book. While I can generally follow and evaluate variations mentally if I can at least see the starting position in some diagram, I struggle after the variations continue beyond the page and I can no longer see a diagram from which the variation departed.
I can copy the diagram on a board or simply on my computer (and do not move the pieces), but I wonder whether I should. On the one hand, being forced to remember and visualize the diagram trains my visualization skill. On the other hand, I catch myself flipping the page quite a few times and I wonder if this distraction is worth the trouble. I certainly don't intend to play blindfold, so I will always have some chess position in front of me when I need it, at least.
Now that I think about it, I'm not even sure whether it is good that I do not play the variations out on a board or computer diagram: I might miss things that the book doesn't want to spend time on, or spend too much effort on skills I should not be training. I have no clue, really.
How can I determine what would work for me here? Are there any texts out there that cover this issue? The book itself doesn't give much suggestions on how to read the variations beyond thinking on your own before reading the suggestions in the book, which I do.

This question is related, but I'm not really looking for what is common, I am looking how I can determine what is good for me, or what chess teachers believe is a didactically effective approach. (based on reasoning or experience)

I can copy the diagram on a board or simply on my computer (and do not
move the pieces), but I wonder whether I should.

It is very much worth while setting up a board and following the game on the board. But you should go beyond just passively playing out the moves on the board. You should stop after each move and actively consider what you would play next for each side. That will benefit you much more.
There is also the aspect of involving more of your 5 senses as I say in this answer to a different question.


Longest period with each piece "hanging" What is the longest period in a real game with a position in which all pieces were "hanging"? The game can also be rapid, blitz
or blindfold, but both players should have at least a 2000 ELO.
To clarify, all of the pieces, except the pawns, must be still on the board and be takeable by the opponent, if the opponent has the move. Of course, the kings are not considered. A check is allowed but not necessary. It is not necessary that this capture would make sense (it is enough that a covered knight is "attacked" by a queen).
I do not think that such a position, if existent, "survives" very long, but perhaps someone will find a nice example.

Since a game with all 14 pieces, as kings are excluded, hanging has probably not happened yet, and will not for a long time, I will answer as best as I can. Under these circumstances, I think that the best that can be done is to locate the highest number possible.
The highest that I have found so far is
6 hanging pieces. I found the full score on chessgames.com. In the board position on move 23, Black can capture three White pieces, and likewise White can also capture three Black pieces.
[Title "Loal W Davis-Magesh Chandran Panchanathan, HB Global Chess Challenge, Minneapolis Minnesota USA, 5/19/2005"]
[FEN ""]
[startply "45"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. exd5 Na5 6. Bb5+ c6 7. dxc6 bxc6 8. Be2 h6 9. Nf3 e4 10. Ne5 Bd6 11. f4 exf3 12. Nxf3 O-O 13. d4 Rb8 14. a3 Re8 15. O-O c5 16. Nc3 cxd4 17. Qxd4 Nc6 18. Qh4 Bf5 19. Bd3 Bc5+ 20. Kh1 Bxd3 21. cxd3 Qxd3 22. Bxh6 Rxb2 23. Na4 Rc2 24. Nxc5 Rxc5 25. Bg5 Ne4 26. Bf4 Rc2 27. Ng5 Nxg5 28. Qxg5 Nd4 29. Rfe1 Rce2 30. Rxe2 Qxe2 31. h3 Nc2 32. Rc1 Qe4 33. Bg3 Ne3 34. Bf2 f6 35. Qxe3 Qxe3 36. Bxe3 Rxe3 37. Ra1 a5 38. Ra2 a4 39. Kg1 Kf7 40. Kf2 Rc3 41. Rb2 Rxa3 42. Rb7+ Kg6 43. Ra7 Ra1 44. Kg3 a3 45. Kf2 Kh6 46. Ra5 g6 47. Kg3 Ra2 48. Kf3 f5 49. Ra7 Ra1 50. Kf2 f4 51. Ra8 a2 52. Ra5 f3 53. Kg3 Kg7 54. Ra6 Kf7 55. Kf2 Ke7 56. Kg3 Kd7 57. Kf2 Kc7 58. Ra3 Kb6 59. Ra8 Kc5 60. Rc8+ Kb6

However, if you wish for "pure" position with all pieces hanging, I discovered a beauty on chessgames.com. It holds yet another 6 hanging pieces in the final position after the climactic 33. Be4!
[Title "Veselin Topalov-Alexander Morozevich, NAO Masters, Cannes France, 2/22/2002"]
[FEN ""]
[startply "64"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O b5 6. Bb3 Bc5 7. a4 Rb8 8. c3 d6 9. d4 Bb6 10. axb5 axb5 11. Na3 O-O 12. Nxb5 Bg4 13. Bc2 h6 14. dxe5 Nxe5 15. Nbd4 d5 16. exd5 Qxd5 17. h3 Bh5 18. g4 Nfxg4 19. Nxe5 Nxe5 20. Qxh5 Bxd4 21. Qf5 Nf3+ 22. Kh1 Qxf5 23. Bxf5 Bf6 24. Ra7 c5 25. Be4 Ne5 26. Rd1 Nc4 27. Bb7 Bg5 28. Bxg5 hxg5 29. b3 Ne5 30. Rd5 Rfe8 31. Rxc5 Re7 32. Rb5 Nd3 33. Be4

Lastly, just for giggles, the fastest way reach to such a position is a mere 6 moves.
[title "me, chess.stackexchange.com 10/16/2020 Non-Unique Proof Game In 6.0"]
[FEN ""]

1. e3 e6 2. Qh5 Qh4 3. Qxh7 Qxh2 4. Ba6 Ba3 5. Bxb7 Bxb2 6. Nc3 Nc6

On a semi-related note, the record for the longest time a piece was “hanging” is 24 moves, during which the Black knight on g4 could have been captured by White's h-pawn. Tim Krabbe has it in his "Chess Records" of course, although the score comes from chessgames.con
[Title "Anthony Miles-Ljubomir Ljubojevic, Interpolis 10th, Tilburg Netherlands, 1986"]
[FEN ""]

1. Nf3 c5 2. c4 g6 3. e4 Bg7 4. d4 Nc6 5. dxc5 Qa5+ 6. Nfd2 Qxc5 7. Be2 d6 8. O-O Nd4 9. Bd3 Nf6 10. Nb3 Nxb3 11. axb3 Ng4 12. h3 h5 13. Qd2 Qe5 14. f4 Qc5+ 15. Kh1 Bd7 16. Nc3 e6 17. Qe2 Bd4 18. Bd2 Qb6 19. Nd1 a6 20. Ba5 Qa7 21. Bb4 Qb6 22. Ba5 Qc6 23. Qe1 e5 24. Bb4 Qb6 25. Ba5 Qa7 26. f5 gxf5 27. exf5 Bc6 28. Be4 Kd7 29. f6 Rag8 30. Bxc6+ bxc6 31. Qe4 Qb7 32. Bc3 Ba7 33. b4 Kc8 34. c5 dxc5 35. Qf5+ Kb8 36. Bxe5+ Ka8 37. bxc5 Bxc5 38. Bg3 Ba7 39. Qd3 Ne3 40. Rf3 Rd8 41. Bd6 Nxd1 42. Qxd1 Rhg8 43. b4 Rg5 44. Rd3 c5 45. Bg3 Rgd5 46. Rxd5 Qxd5 47. Qa4 cxb4 48. Qxa6 Qb7 49. Qf1 Rd7 50. Bf2 Qc6 51. Bg1 Rb7 52. Qf2 Qd7 53. Qf3 Kb8 54. Qf4+ Ka8 55. Qe4 Kb8 56. Bxa7+ Rxa7 57. Qxb4+ Ka8 58. Qf8+ Kb7 59. Rxa7+ Kxa7 60. Qe7


Question about solutions given in a chess book for mate-in-two and mate-in-three I recently purchased the book "Chess: 5334 Problems, Combinations, and Games" by Laszlo Polgar, just to learn more about moves.

This book has 3411 "Mate in two" problems and 743 "Mate in three" problems. The book is great but I have a question about the solutions to these problems.

For example, the solution to this mate-in-two (white to move first) problem # 1135 (from p. 247)...

[FEN "rkn5/pp1R4/2pn4/2N5/8/8/8/K w - - 0 1"]

...is given (in figurine algebraic notation) as:

Rb7

The solutions to both the mate-in-two and the mate-in-three problems list only one step (the book does not explain the reason for this).

How should a person read this solution? Is it the supposed final location of the white rook? And is this way of listing solutions common practice in chess books?

I think it's slightly unusual to only give the first move, or a little outdated. But it saves space and the assumption is that if you found the right solution, you can confirm it by seeing the first move.

I also think that Polgar originally intended this book (and his other "big books") as a collection of problems for coaches to select problems for their students from, because doing 5000+ mate in 2 and mate in 3 problems is a bit much for self-study. The coaches are expected to be of sufficient strength already, and to be able to select some problems with a common theme that they need for some lesson.

The whole answer, in this case, is of course 1.Rxb7+ Nxb7 (forced) 2.Na6#.

The 'x' and '+' in Rxb7+ are strictly speaking not necessary, so some books omit it. Again, that's a bit of an outdated practice since it's just not that user friendly.


Information on adding opening knowledge to an engine I'm writing a chess engine in C# for school purposes. As part of the assignment, I need to read something from an external document. I was thinking of reading an opening book, but I can't really find much documentation because Polyglot is used a lot of the time. I can't really use that because I don't get marks for other people's code.
Does anyone have information or a good website on how to implement a png/bin opening book in your chess engine?

there are plenty of free online files of chess openings, here are a few:
https://www.pgnmentor.com/files.html#openings
http://scid.sourceforge.net/
https://www.bookup.com/ECO/chess_openings_ECO_-.htm
i could only find these links as of now. I will give you more once i find more


Stockfish 10 working on only 1 core at a time I am a lichess user who would like to be able to use my 8C/16T processor to the best of my ability, and yet when I start up a chess engine only one of my cores is working on stockfish the rest are either doing very very little of just nothing at all. Why is this happening and how can I fix it?

I am using Linux (Ubuntu 18.04 LTS)

This is what I was told on lichess forums:

Both javascript.options.shared_memory and dom.postMessage.sharedArrayBuffer.withCOOP_COEP have to be set to true.

As a very new linux user... how do I actually implement this?

Those appear to be options to set in your Web browser, which is effectively the platform that LiChess runs on.  You don't mention which browser you're using…

Chrome uses multiple cores and thereby searches many more nodes per second, without any special attention.

On my Mac, Firefox uses only one core, even after entering the settings you mention (using about:config).  However, the Linux version responds well to these settings.

Obviously, a native chess engine would be more efficient still.  This wouldn't integrate with LiChess, however.


analyse and store a annotated game by stockfish in scid Salut

I installed scid and set all necessities in order to make an analysis by stockfish, but I could not find the option to save the done analysis.

My question is just silly but I cannot find simply this function.

Thanks for your answers!

*could you propose a method whereby I could make analyses of several games by an engine which also stores all analyses so that I could watch later to them?

In the Game menu, there's a Save: Replace Game option.  If you choose this after doing your analysis, the analysis should be saved.


Why does Stockfish suggest capturing a bishop in this position when my opponent can fork my king and rook? The position in question is:

[FEN ""]
[StartPly "13"]

1. d4 c5 2. Nf3 cxd4 3. Nxd4 Nc6 4. Nc3 e5 5. Ndb5 Bb4 6. Bg5 Bxc3+ 7. bxc3 Qa5 8. Qd5 Nge7 9. Nd6+ Kf8 10. Qxf7# 1-0

It's black turn and the engine is recording to take the hanging bishop, but doesn't Nc7+ fork the King and the Rook? Stockfish is still showing a negative evaluation for this position.

Am I missing something important?

White does indeed fork the king & rook after Nc7+ - but after Nxa8, the knight is not escaping, so Black is at worst even on material.

 [FEN ""]

 1. d4 c5 2. Nf3 cxd4 3. Nxd4 Nc6 4. Nc3 e5 5. Ndb5 Bb4 6. Bg5? Qxg5 7. Nc7+ Kd8 8. Nxa8

After something like ...b6 followed by Bb7, the knight's a goner. White can get at most one pawn for the knight (after Nxb6), which leads to a material imbalance of R+P vs B+N. This particular imbalance is roughly equal, although I've also read that the side with two minors tends to be favored in middlegames since they represent two useful attacking pieces while the extra pawn is only useful in the endgame. Moreover, Black is also way ahead in development (even if he does take some time to round up the knight on a8).

In short, you're not missing anything important insofar as White does not end up grievously behind in material - but Black has more than enough positional compensation.


Rook ending with single distant passed pawn 6k1/1R5p/6p1/p7/8/7P/r5P1/6K1 w - a6 0 33

Is it possible for White to hold a draw in this position? If so, what is the strategy?

Typically I lose these ones and draw when it's me with the extra pawn...

This should be a draw as far as I know and the first step is to get behind the pawn with your rook. Now if black pushes the pawn to the second rank it is an easy draw, because he can never move the rook without you taking the a-pawn and if he tries to protect the a-pawn with the king you will just give checks from behind.

8/R6p/6p1/8/8/1k5P/p5PK/r52 w - a6 0 33

In this position you just check with Rb8+ and go on checking until his king leaves the a-pawn. Then you go straight back to attacking the a-pawn otherwise Rh1+ wins for black.

So what he might try is pushing the pawn only to a3. Then he has a place on a2, to hide his kings from the checks. But now the problem for black is that he doesn't threaten to move his rook away and queen the pawn, therefore your rook isn't shackled to the a-pawn. That means as soon as his king leaves the kingside pawns, you just snatch them off with your rook.

8/8/R5p1/5k1p/7P/p5K1/6P1/r52 w - a6 0 33

Something like …Ke4 Rxg6 Kd4 Rg5 Kc3 Rxh5 Kb2 Ra5 ...

Given that his king has to run all the way to the a-line, then move the rook and make two pawn moves to queen the pawn, this should give you enough time to push your own kingside pawns. When you finally have to give your rook for the a-pawn, ideally your kingside pawns (supported by your king) are so far advanced that his rook cannot deal with them.


Tools for automated notation: webcam movie to PGN Sometimes during blitz games over the board, or when in zeitnot, it gets very difficult to annotate them.

I've seen several software / hardware to help in writing the notation, even one that's FIDE approved; these require that you repeat the moves on the device. Hardly faster than pen and paper, just as prone to errors, plus you risk typing the wrong move and wasting even more time.

DGT makes a board that will do this automatically, but it will only work with its pieces, and starts at 400€, double that for tournament boards.  Some independent projects are available such as usb chessboard 101, or voice controlled chess robots, Chess board step sequencer.  Additionally some open projects are available that even move pieces (or gigantic pieces).

I have a playoff tonight, and the tournament rules dictate shorter and shorter games until there is a winner.  Hence I thought about shooting a movie of the board should we lose track.  But then my programming background kicked in and I thought "there must be some software that can process a movie and write the PGN".

I searched everywhere, and found nothing.

Does any such thing exist (webcam/video to pgn converter)? A prototype maybe?
Has anyone attempted such a feat and shared their research?
Are there obvious limitations that make this project unlikely to succeed?
Would you buy it if it existed?

It's 2019-12 now and 5 years after the original question.

Does any such thing exist (webcam/video to pgn converter)? A
prototype maybe?

see

https://github.com/WolfgangFahl/play-chess-with-a-webcam/issues/19
https://github.com/WolfgangFahl/play-chess-with-a-webcam/issues/22
which are both closed by now. See http://lichess.bitplan.com for a game successfully recorded. Join https://gitter.im/play-chess-with-a-webcam/community to discuss

Has anyone attempted such a feat and shared their research?

Yes - so far I found some 35 research papers and some 10 open source solutions and one commercial offering

2.1  http://wiki.bitplan.com/index.php/PlayChessWithAWebCam/Papers

2.2. http://wiki.bitplan.com/index.php/PlayChessWithAWebCam#Open_Source_Projects

2.3. http://wiki.bitplan.com/index.php/PlayChessWithAWebCam#Commercial

http://wiki.bitplan.com/index.php/PlayChessWithAWebCam is another project
aiming at the goals stated by you. The project was started 2019-10-15 and in a few hours I already found a lot of resources e.g. this Question
Some two months later I have updated my answer (see links above)
Are there obvious limitations that make this project unlikely to succeed?
I can only answer from my own experience with a similar project I did 31 years ago see http://wiki.bitplan.com/index.php/MagneticSensorChessBoard1987.
At that time i tried to create a chess board that would detect moves. I used magnets
in the wooden pieces and reed contacts. The key to success was using a chess engine
that new "the rules" to be able to concentrate on movements alone and not having
to detect individual pieces. As outlined in an answer above promotions to non queen
pieces might be one of the edge usecases that are difficult. Detecting the motion of
pieces via picture differences is a well understood problem.

Chess engines and UCI compatible GUIs are also available these days. So the problem
is more an integration problem these days then solving the individual detail issues.

A major obstacle is the difference between a "prototype" and a product. See e.g.
http://www.nandanbanerjee.com/files/ICCVR-08AUG12-011%20paper.pdf

a paper that is even older than this question but far from a product that you can buy
at a reasonable price.
Would you buy it if it existed?

Yes. When I bought a new chess board a few days ago I was looking for one that
could record moves and it was still around 500 EUR. As it looks the hardware cost
will be well below 150 EUR these days including a decent chess board and pieces.

The software might well be opensource and free (as in free beer) soon. I'll update
this answer accordingly.


If I like both the Caro-Kann and the Slav, is it a good idea to answer 1. d4 with 1... c6? I was just wondering, if as Black I normally play the Caro-Kann and the Slav (but I slightly prefer the Caro-Kann), is it a good idea to answer 1. d4 with 1... c6!?

I looked in an opening database, but it looks like 1... c6 is extremely rare and is only played 0.3% of the time.
What's wrong with it? Doesn't it just transpose into either a Slav or a Caro-Kann?

Does it have a psychological effect on weak opponents? Maybe they will be a little surprised, and thus they will take slightly more time to make their second move, and so it would be an effective subterfuge especially in blitz.

I don't think it's a good idea. Firstly, no 1.d4 player will go for 2.e4, unless they are also 1.e4 players and really, really good at playing against the Caro-Kann.

More importantly, you may like to play the Slav against d4+c4, and the Caro against d4+e4, but so far white has only played 1.d4. You lose options in case white doesn't follow up with a quick c4 or e4.

Mostly that's lines like the London (say 2.Nf3 and 3.Bf4) or the Colle (with Nf3, e3, Bd3, possibly b3 and Bb2, etc). Against both of those, black's best chance to get an active game are with a quick ...c5, but if you do that you've already given up a tempo.

So there is a downside, and zero upside.


How should one decide which rook to put on a central file? How should one decide which rook to put on a central file? I usually just move the one which is closer to the file, unless there are weak squares in my position that one rook is defending. In positions where there are no weak pawns, how should I decide whether to move the rook of the side to which I castled or the other?

Essentially, you should ask yourself a broader question: where should both of my rooks go in this position? There might be another (half-)open file which can be used by the other rook. If there's only one open file and little chance of another one opening or a pawn needing extra protection, it might not even matter which rook you use, since it's rather likely for the rooks to be doubled up on the same file anyway.

[FEN "r4rk1/ppp2ppp/3p4/8/8/3P4/PPP2PPP/R4RK1 w - - 0 1"]

In a position like this (ignoring the position of other pieces) it's more common to move Rfe1, since the chance that one of the a, b and c pawns needs extra protection combined is greater than the chance that f2 becomes weak. Indeed, that's the nearest rook, as you already mentioned.


How do you apply schematic thinking to one's own chess games? I can never figure out how to come out with many micro plans in an endgame. I'm not sure in which order they should be applied as well. How do you apply schematic thinking to one's own endgames?

There is an excellent book by GM Jonathan Hawkins called "Amateur to IM" which deals with this. There are a number of stages you need to go through.

First of all when looking at a mini plan you need to consider a) will it work, or can my opponent easily stop it and b) if it does work will it actually do what I want it to do - give me a winning position, say.

So, for instance, if you can force an exchange into a BPKvK endgame you might think you have an easy win, but if the pawn is a rook's pawn on the wrong side of the board then you will be disappointed. You can only know the mini plan was a bad one if you can properly evaluate the final position.

Hawkins aims to do two things in the book. First to help you to think the right way about endgame positions so that you evaluate mini plans and quickly eliminate those that aren't going to do the job and not waste any more time on them. Second to help you build the knowledge of endgame structures that will enable you to correctly evaluate the final positions of your mini plans.

Hawkins points out that the big advantage that stronger players have in the endgame is not their ability to calculate much longer variations much quicker (generally speaking they don't have this!) but their ability to quickly and correctly evaluate candidate positions that they are aiming for. They are not high speed calculators. They are very good evaluators who don't waste time calculating mini plans which they know in advance are not going to work, so saving time and making it look like they are high speed calculators!


Books dealing with the g3 Queen's Indian What are the best repertoire or opening books, if any, advocating the g3 variation vs the Queen's Indian for White, in terms of analysis and verbal explanations of the main plans / ideas?

I will have to explore through some of the new (and older) literature on the Queen's Indian to give you better recommendations, but off the top of my head I recall at least 3:

Play the Queen's Indian by Andrew Greet: if I remember correctly the fianchetto variations are discussed somewhere at the end of his book. One plus about this book is that it's quite readable.
Starting Out: The Queen's Indian by John Emms: This is probably what you're looking for, there's an extensive study on the g3 variation (up to 70 pages almost). Also see his post here.
Queen's Indian Defence by Jacob Aagaard: I've heard good things about this one, but haven't read it myself, see chapter two. Apparently it contains numerous references to insightful games, for whatever variation that is covered in the book.

Finally, to browse through the known variations and played games, there are many websites that you can look through, but these two should get you started:

365chess
Queen's Indian (E15) page on chessgames


Is blocking a check with a check an illegal move? Say my opponent puts me in check. If I move my queen to block the check and it also puts my opponent in check, is that legal?

Yes, it is legal, since your king is no longer being attacked.


In Swiss tournaments, is it common to play weaker players when playing White? I was looking at the statistics for my tournament games in SCID, and found something surprising. When I played opponents rated under 1000, 13 out of 15 times I've had White. Conversely, when I played opponents rated 2000 or higher, 10 out of 15 times I've had Black.

I'd accept 10 out of 15 as being coincidence. But 13 out of 15 seems unlikely to happen purely by chance; the odds are less than 1%.

Is there a reason why a person would tend to play stronger players as Black and weaker players as White? Or is it just a coincidence?

Your 1% chance calculation is wrong, because "observations" are not independent from each other within a single tournament. When you play one round as White, you are very likely to play the following one as Black. Also, after a win, you are very likely to face a stronger player in the next round. So your tournament could go something like this.

WHITE, weak opponent. WIN

BLACK, strong opponent. LOSE

WHITE, weak opponent. WIN

... (you get the idea)

This means that if, in 3 consecutive tournaments, you get to play a weak opponent as White (let's say that, by ranking, you are about 100th in a pool of 200 players), you can easily get pairings such as those you are showing (with a 1 in 8 chance, and also a 1 in 8 chance of getting the exact opposite)