05 May 2013

Commentary - 2013 U.S. Championships, Round 2

For Round 2 of the U.S. Chess Championships I found an embarrassment of riches - 5 games that I thought were particularly relevant to my chess training and studies, not just one.  I was fortunate to be able to see a large portion of the excellent live coverage for round 2 as well, giving me some ideas of which games were the most interesting to me personally, along with some specific observations and ideas from the commentary.

Game 1: IM Kayden Troff - GM Gata Kamsky
Kamsky brings out the Leningrad Dutch, which his opponent likely was not fully prepared for, judging by the novelty on move 7.  Black makes a strategic exchange sacrifice and then takes over the initiative and outplays his opponent.  I found both the opening discussion and the idea and execution of the positional exchange sacrifice very useful to see.

[Event "2013 U.S. and Womens' Championship"] [Site "Saint Louis, Missouri, USA"] [Date "2013.05.04"] [Round "2.1"] [White "Troff, Kayden"] [Black "Kamsky, Gata"] [Result "0-1"] [ECO "A86"] [WhiteElo "2421"] [BlackElo "2741"] [Annotator "ChessAdmin/Houdini"] [PlyCount "64"] [EventDate "2013.??.??"] [TimeControl "6000+1455"] [WhiteClock "0:01:28"] [BlackClock "0:10:01"] 1. d4 f5 2. c4 Nf6 3. Nc3 d6 {Leningrad Dutch players use this move-order to avoid giving a target to a quick h4-h5 attack by White.} 4. g3 (4. h4 {is now rarely played, but has been highly effective, scoring 80 percent in the database, including against strong Black players. Black can now play in the center, however, and is not committed to g6. An example:} e5 5. dxe5 dxe5 6. Qxd8+ Kxd8 7. Nf3 Nbd7 8. e4 f4 9. g3 fxg3 10. fxg3 Bb4 11. Bg5 h6 12. Bxf6+ gxf6 13. Rc1 Rg8 14. Kf2 c6 15. Bd3 Ke7 16. a3 Bc5+ 17. Kg2 a5 18. h5 Be3 19. Rce1 Bf4 20. Ne2 Nc5 21. Bc2 Be6 22. Kf2 Bg5 23. b3 Bg4 24. Rd1 Rad8 25. Nc3 Rxd1 26. Bxd1 Rd8 27. Nh4 Rd2+ 28. Kf1 Bxd1 29. Nf5+ Ke6 30. Ke1 Nd3+ {0-1 (30) Hambleton,A (2052)-Barron,M (2241) Edmonton 2009}) 4... g6 5. Bg2 (5. h4 { has never been played in this position in the database, but the following game is an example by transposition at the professional level.} c6 6. Bg2 Qa5 7. Bd2 Qa6 8. b3 Bg7 9. d5 O-O 10. Nh3 cxd5 11. cxd5 Nbd7 12. Nf4 Ne5 13. h5 Bd7 14. hxg6 hxg6 15. Be3 Nfg4 16. Bd2 Qb6 17. O-O Rfc8 18. Rc1 Bf6 19. e3 {1/2-1/2 (19) Djurhuus,R (2495)-Sahl,B (2455) Gausdal 1995}) 5... Bg7 6. Nh3 { characteristic of the Karlsbad variation. White chooses not to block the Bg2 and normally looks to move the knight to f4.} e6 {an uncommon move here, although e6 is played in the main line Karlsbad. The pawn move has the dual purpose of contesting d5 and allowing Black the option of playing an eventual . ..e5 if White pushes d5.} (6... c6 {scores 50 percent in the database and is the popular choice for those not wanting to commit the knight via ...Nc6.}) 7. Qa4+ $146 {this early queen sortie has not been played before in the database. Castling or playing Nf4 are the two most popular options.} c6 8. d5 O-O 9. dxe6 Bxe6 $11 {this is another idea behind the earlier e6, to allow the pawn exchange and bishop development.} 10. Ng5 Bc8 {an interesting choice, disallowing the knight for bishop exchange. Black's bishop currently is quite confined, but may have good long-term prospects.} 11. O-O Qe7 12. Qa3 Nbd7 13. Rd1 Ne8 {this sort of passive defense seems like an attempt to bait White into overextending himself.} (13... h6 14. Nh3 Ne5 {and now} 15. Qxd6 Qxd6 16. Rxd6 Nxc4 {seems good for Black.}) 14. Be3 Ne5 {Kamsky must have seen the following sequence (except perhaps for the move 16 variation) and evaluated that he could play the position following the exchange sac better than his opponent.} 15. c5 dxc5 16. Bxc5 (16. Nd5 {is what Houdini comes up with, a far from obvious move that however gives White an attack.} cxd5 17. Bxd5+ Kh8 18. Bxc5 Qxg5 19. Bxf8 $16 {with strong pressure and open lines in the center for White to exploit, for example} Qf6 20. Bxg7+ Kxg7 21. Rac1) 16... Qxg5 17. f4 Qf6 18. fxe5 Qxe5 19. Bxf8 (19. Rd8 {here would be annoying for Black, an idea flagged by the live commentators.}) 19... Bxf8 20. Qb3+ Kg7 $11 {Houdini evaluates this as equal, despite the small material imbalance in White's favor. Kamsky must have been confident that he could exploit his longer-term structural advantages and White's weaknesses (such as the e-pawn), despite his own backward development. The collection of pieces on the 8th rank is impressive in that regard.} 21. Bf3 {White's first move that goes a bit astray.} (21. Rd8 {now doesn't work due to} Nd6 {effectively trapping the rook, forcing White to give back the exchange.}) (21. e4 {was Seirawan's idea during the live commentary and is also Houdini's favorite. White looks to exchange off the weak pawn, or if Black leaves it on the board, gain some control over the center.}) 21... Nd6 22. Na4 Nb5 23. Qd3 Be6 $15 {compare this position with three moves earlier, Black looks much better positioned while White has essentially done nothing constructive.} 24. Kg2 g5 {signals that Black has taken over the initiative.} 25. Kh1 Be7 26. Qc2 g4 27. Bg2 h5 {Black now has a kingside attack rolling with all of his pieces poised to participate (even the knight can jump in via d4). In constrast, White's pieces are spread out and uncoordinated.} 28. e4 h4 29. exf5 Bxf5 30. Qc4 h3 {with the pawn on h3 and open lines available for Black's pieces to attack White's king, the end is near.} 31. Re1 hxg2+ 32. Kxg2 Qf6 $19 {Houdini evaluates the position as the equivalent of Black being up a piece.} 0-1

Game 2: GM Gregory Kaidanov - GM Conrad Holt
It's always difficult to face your own favorite defense as White, so this game was personally important, as I've struggled to come up with a good reply after 1...c6.

[Event "2013 U.S. and Womens' Championship"] [Site "Saint Louis, Missouri, USA"] [Date "2013.05.04"] [Round "2.5"] [White "Kaidanov, Gregory"] [Black "Holt, Conrad"] [Result "1/2-1/2"] [ECO "A11"] [WhiteElo "2593"] [BlackElo "2513"] [Annotator "ChessAdmin/Houdini"] [PlyCount "120"] [EventDate "2013.??.??"] [TimeControl "6000+1205"] [WhiteClock "0:05:11"] [BlackClock "0:00:40"] 1. c4 c6 2. Nf3 {an independent English variation. Naturally White could transpose to a queen or king's pawn opening here.} d5 3. g3 Nf6 4. Bg2 dxc4 5. O-O Nbd7 6. Na3 (6. Qc2 {is the other main option.} Nb6 7. a4 (7. Na3 { transposing})) 6... Nb6 7. Qc2 Be6 {this position demonstrates White's objective with sacrificing the pawn. Black's kingside is underdeveloped and his king is in the center, while White has a lead in development and is pressuring hard to regain his pawn.} 8. Ne5 (8. Ng5 {is played the most, but only scores 45 percent for White. The text move scores 52 percent.}) 8... Qd4 9. Nxc6 bxc6 10. Bxc6+ Kd8 11. Bxa8 {only a handful of games in the database now, the only game with this move being a White loss.} (11. Nb5 {is Houdini's choice and was most recently played by Timman in Wijk aan Zee:} Qc5 12. Bxa8 Qxb5 13. Bg2 h5 14. h4 Bf5 15. e4 Bd7 16. a4 Nxa4 17. e5 Ne8 18. Re1 e6 19. Bf1 Bc5 20. d3 Qb3 21. Qxc4 Qxc4 22. dxc4 Nc7 23. Rd1 Kc8 24. Rxd7 Kxd7 25. Rxa4 Rb8 26. Be2 g6 27. Bd1 Bd4 28. b3 a6 29. Bf4 Bc3 30. Ra2 Kc6 31. Kf1 a5 32. Bd2 Bb4 33. Bxb4 axb4 34. Bf3+ Kb6 35. c5+ Kb5 36. Rd2 Nd5 37. Bxd5 exd5 38. Rxd5 Rb7 39. Ke2 Kc6 40. Rd3 Re7 41. f4 Ra7 42. f5 gxf5 43. Kf3 Ra1 44. Kf4 Rf1+ 45. Kg5 Kxc5 46. Kxh5 Rc1 47. Rf3 Rc3 48. Rxf5 Kd5 49. g4 Ke6 50. Rf6+ Ke7 51. g5 Rxb3 52. e6 fxe6 53. Kg6 Rh3 54. h5 b3 55. h6 {1-0 (55) Timman,J (2566)-Smeets, J (2615) Wijk aan Zee NED 2013}) 11... Nxa8 {in contrast with the other line, now White no longer has the two bishops.} 12. d3 cxd3 13. Rd1 dxc2 14. Rxd4+ Bd7 15. Nxc2 e5 16. Rd1 Nb6 17. Be3 Kc7 18. Ne1 {during the live commentary, a small preference was given to Black here because two pieces usually are more powerful than a rook. Black also has plenty of good squares for his pieces at this point.} Nfd5 19. Rac1+ Kb7 20. Bc5 {standard practice when your opponent has the two bishops is to trade one of them off.} Bxc5 21. Rxc5 Be6 22. Nd3 e4 23. Ne5 {Houdini evalutes this position as completely equal. Despite the R+P vs. B+N imbalance in his disfavor, White's rooks are well-placed as is his knight, while Black's king looks a little precarious.} Ne7 24. Rd4 f6 {this may have been a psychological turning point in the game, as White afterwards starts to gain some initiative. The eventual tactical point of White's sequence may not have been seen.} (24... Bd5 $5) 25. Rxe4 Bd5 26. Rg4 fxe5 27. Rxg7 {pinning the Ne7, which either results in the return of a piece (leaving White two pawns to the good) or ties Black up in knots.} Re8 28. e4 Bg8 29. Rxe5 Nbc8 30. b3 $14 {the material balance in a rough sense somewhat favors Black, but the dominance of the White rooks and Black's passive piece placement, along with White's mobilizing passed pawns, give White an advantage. } Kc7 31. f4 Kd6 32. Kf2 Rf8 33. Ke3 Nc6 34. Rh5 N8e7 35. h4 Ke6 36. g4 Kf6 37. Rgg5 {the live commentary picked things up again here, noting how the rook and pawn activity and related space advantage was in White's favor. The position is tough to play, however, and neither player is likely to have much in the way of similar experience to draw on.} Rd8 38. Rc5 (38. Rh6+ Kf7 39. Rc5 $16 { is Houdini's preference, pushing the king back before playing ...Rc5.}) 38... Kg7 39. Rc3 Rd1 40. Rg5+ Kf8 $11 {here Houdini gives a slight edge to Black, who has managed to activate his pieces and get his king to a less vulnerable square.} 41. f5 Rd6 (41... Ne5 $5) 42. Rc5 h6 (42... Bf7) 43. e5 {Houdini thinks this is winning for Black.} (43. Rxg8+ Kxg8 44. a3 $15) 43... Rd5 44. Rxg8+ Kxg8 45. Rxd5 Nxd5+ 46. Kf3 Nc3 47. e6 Nxa2 48. g5 hxg5 49. hxg5 Nc3 50. Ke3 Kf8 51. Kd3 Nd5 52. Kc4 Nc7 (52... Ne3+) 53. Kc5 Nb8 {now White's king pushes forward and Houdini evaluates the position as equal. White threatens to push the pawns forward with the king's help, but cannot escape from the Black knights' harrassment.} 54. Kd6 Ne8+ 55. Kd5 Nc7+ 56. Kd6 Nb5+ 57. Kc5 Nc3 58. Kd6 Nb5+ 59. Kc5 Nc3 60. Kd6 Nb5+ 1/2-1/2

Game 3: GM Melik Kachyan - GM Alex Onischuk
This is an excellent example of a solid Caro-Kann Classical, whose main line goes out quite far (around move 20).  Black neutralizes White's threats and plays solidly, although White perhaps could have tried for a little more towards the end.

[Event "2013 U.S. and Womens' Championship"] [Site "Saint Louis, Missouri, USA"] [Date "2013.05.04"] [Round "2.6"] [White "Khachiyan, Melik"] [Black "Onischuk, Alex"] [Result "1/2-1/2"] [ECO "B19"] [WhiteElo "2518"] [BlackElo "2666"] [Annotator "ChessAdmin/Houdini"] [PlyCount "71"] [EventDate "2013.??.??"] [TimeControl "6000+1225"] [WhiteClock "0:24:42"] [BlackClock "0:11:10"] 1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 Nd7 8. h5 Bh7 9. Bd3 Bxd3 10. Qxd3 e6 11. Bd2 Ngf6 12. O-O-O Be7 13. Ne4 Nxe4 14. Qxe4 Nf6 15. Qe2 Qd5 16. c4 Qe4 17. Qxe4 Nxe4 18. Be3 {a standard opening line to this point, where we now have a queenless middlegame that can simplify quickly into an endgame.} Nd6 {a solid choice that scores 50 percent for Black.} (18... f5 {scores the best here, with 56 percent for Black.}) (18... O-O {is the most popular, but only scores 47 percent for Black.}) 19. Ne5 Bf6 20. b3 Nf5 21. Nf3 b5 22. g4 {first move out of the database.} Nxe3 23. fxe3 bxc4 24. bxc4 c5 { a typical pseudo-sacrifice that if accepted would give Black a small advantage. } 25. Kc2 (25. dxc5 Rc8 26. Rd2 Rxc5 27. Rc2 Ke7 $15 {and Black has two isolated pawns to target.}) 25... O-O 26. Kd3 Rac8 27. Rh2 Rfd8 28. Rc2 Rd6 29. Ke4 Rb6 30. Rd3 Rb4 (30... Ra6 {would be safer.}) 31. Rb3 (31. Ra3 $5 cxd4 32. exd4 Rbxc4 33. Rxc4 Rxc4 34. Rxa7) 31... Ra4 32. Rb7 Rc6 33. Rb8+ Kh7 34. Rb7 Kg8 35. Rb8+ Kh7 36. Rb7 1/2-1/2

Game 4: GM Alejandro Ramirez - GM Alexander Ivanov
The opening phase is very interesting, morphing from a Hedgehog to a Symmetrical English to a Benoni structure.  White has a comfortable game afterwards, although not a winning advantage.  The explosion of tactics starting on move 19 comes from what appears to be just a small Black inaccuracy.  White aggressively pushes the passed pawn he wins as a result and leverages other associated tactical opportunities to ram home the point.

[Event "2013 U.S. and Womens' Championship"] [Site "Saint Louis, Missouri, USA"] [Date "2013.05.04"] [Round "2.9"] [White "Ramirez, Alejandro"] [Black "Ivanov, Alexander"] [Result "1-0"] [ECO "A30"] [WhiteElo "2551"] [BlackElo "2544"] [Annotator "ChessAdmin/Houdini"] [PlyCount "67"] [EventDate "2013.??.??"] [TimeControl "6000+1640"] [WhiteClock "0:35:30"] [BlackClock "0:02:06"] 1. Nf3 Nf6 2. c4 b6 3. g3 c5 4. Bg2 Bb7 5. O-O Nc6 {this move varies from a the typical Hedgehog setup.} 6. Nc3 g6 7. e3 (7. d4 {would be the standard analagous continuation in a Hedgehog and in fact scores over 70 percent for White. The text move also scores well, 65 percent.}) 7... Bg7 8. d4 {now White would be able to replace the pawn on d4 if it is exchanged.} O-O 9. d5 { as Black declines to exchange on d4, White now grabs space with d5. The pawn structure is now that of a more typical queen's pawn opening.} Na5 10. Qd3 e6 { Black decides to immediately challenge the head of the pawn chain.} 11. e4 exd5 12. exd5 d6 {now we have a Benoni-type structure. White appears to have a comfortable game.} 13. Bf4 Bc8 14. b3 Bf5 15. Qd2 Re8 16. Rae1 Qd7 $6 {this cuts off the retreat squares for the Bf5.} (16... Nb7 $5) 17. Nh4 Nb7 18. Nb5 { this perhaps was played to see if Black would go wrong before the capture.} ( 18. Nxf5) 18... Nh5 {and Black does. The d6 pawn is vulnerable after the exchange on f5.} (18... Be4) 19. Nxf5 Qxf5 (19... gxf5 20. Rxe8+ Rxe8 21. Nxa7 Nxf4 22. Qxf4 Re2 23. Nb5 h6 24. Bh3 Qe8 (24... Rxa2 25. Re1) 25. a3 $18) 20. Bxd6 Rxe1 21. Rxe1 Nxd6 22. Nxd6 $16 {White is now up a protected passed pawn and Black has no compensation for it.} Qd7 23. Nb5 a6 24. d6 {aggressively pushing the pawn whenever possible. Here the discovered attack on the Ra8 is the tactical mechanism.} Rd8 (24... Re8 $5 $16) 25. Re7 $18 Qf5 26. Nc7 (26. Bd5 {is Houdini's recommended tactic.} axb5 27. Rxf7 Qxf7 28. Bxf7+ Kxf7 29. Qd5+ Kf8 30. Qc6 $18) 26... Nf6 27. Bd5 Nxd5 28. Nxd5 Bf8 29. d7 {more tactics allow the passed pawn push.} Qb1+ (29... Rxd7 $2 30. Rxd7 Qxd7 31. Nf6+) 30. Re1 Qf5 31. Re8 {White now finishes off his opponent with a tactical flourish.} Rxd7 32. Qh6 Qb1+ 33. Kg2 Qe4+ 34. Rxe4 {Black now loses the rook, not having the time to both recapture the queen and move out of the way of the fork with Nf6+} 1-0

Game 5: Sarah Chiang - IM Anna Zatonskih
Zatonskih transposes into a Modern Dutch Stonewall formation by move 6, after starting off with a Slav defense.  Her opponent appears unfamiliar with some key positional ideas, such as the importance of not opening the f-file and trying to maintain a knight on e5.  Despite this, White manages to stay equal after Black fails to follow up on a few opportunities.  In the resulting equal double bishop endgame, Black simply outplays her opponent in an instructive manner.

[Event "2013 U.S. and Womens' Championship"] [Site "Saint Louis, Missouri, USA"] [Date "2013.05.04"] [Round "2.14"] [White "Chiang, Sarah"] [Black "Zatonskih, Anna"] [Result "0-1"] [ECO "A85"] [WhiteElo "2098"] [BlackElo "2466"] [Annotator "ChessAdmin/Houdini"] [PlyCount "86"] [EventDate "2013.??.??"] [TimeControl "6000+1700"] [WhiteClock "0:18:07"] [BlackClock "0:23:43"] 1. d4 d5 2. c4 c6 3. Nf3 e6 4. e3 f5 {naturally Black has several options here; Zatonskih goes for a Stonewall.} 5. Nc3 Nf6 6. Bd3 Bd6 {the Modern Stonewall formation is now complete.} 7. O-O O-O 8. Qc2 Ne4 9. Ne5 Nd7 {this is the most popular continuation and scores 50 percent for Black in the database. Black chooses to avoid exchanging off her dark-square bishop.} (9... Bxe5 10. dxe5 Nd7 {is an alternative line that scores better than 50 percent for Black.}) 10. f3 Nef6 {a rare move.} (10... Nxc3 {is by far the most played here, for example } 11. Qxc3 Nxe5 12. dxe5 Be7 13. Bd2 Qb6 14. Kh1 Bd7 15. Rad1 Kh8 16. Bc1 Be8 17. Bb1 Bh5 18. a3 a5 19. Rd4 g5 20. Re1 g4 21. fxg4 Bxg4 22. h3 Bh5 23. Rf1 Bg5 24. b4 axb4 25. axb4 c5 26. Rd2 cxb4 27. Qb3 Bxe3 28. Rc2 Bxc1 29. Rfxc1 Ra3 30. Qb2 d4 31. c5 Qc6 32. Qxd4 Rxh3+ 33. Kg1 Rg8 34. Rf2 Rhg3 35. Rcc2 Bf3 {0-1 (35) Nazarov,V (2152)-Nagimov,A (2344) Dagomys 2004}) 11. Nxd7 (11. f4 { would be more usual here, keeping the Ne5 established on its square.}) 11... Bxd7 12. e4 $6 {this greatly assists Black's typical plan of opening the f-file for attacking purposes.} (12. b3 {would be a standard way to develop the bishop}) (12. c5 $5) 12... fxe4 13. fxe4 e5 {posing a complex choice for White in the center.} (13... Ng4 {is Houdini's move, with an immediate threat to the h2 pawn.} 14. Rxf8+ Qxf8 15. g3 dxc4 16. Bxc4 {and now} Bc5 {is the key tactic, gaining Black the d-pawn, since} 17. dxc5 $2 Qxc5+ 18. Kg2 Qxc4 $19) 14. exd5 {the engine indicates this is the incorrect selection.} (14. c5 exd4 15. cxd6 dxc3 16. Be3 $11 Qe8 (16... cxb2 $6 17. Qxb2 {and now White threatens the pawn on b7 and pushing e5.})) 14... exd4 15. Ne4 Nxe4 16. Rxf8+ Qxf8 17. Bxe4 h6 {Black takes a moment to move the pawn out of the B+Q battery.} (17... Qf6 {as a more aggressive continuation was also possible, accelerating Black's threats to White's vulnerable king. For example} 18. Bxh7+ $2 Kh8 19. Bd3 Re8 20. Bd2 Qh4 21. g3 Bxg3 $19) 18. Bd2 Re8 {Houdini again likes ...Qf6 here.} 19. Re1 Kh8 {getting out of the way of future potential checks along the g8-a2 diagonal following an exchange on d5, as well as Bh7+.} 20. Qd3 Qf6 21. Qf3 ( 21. dxc6 {would ensure that Black' s queenside pawns are split in the coming endgame.}) 21... Qe5 22. g3 Rf8 23. Qg2 Qh5 24. Rf1 Rxf1+ 25. Qxf1 c5 {the engine evaluates the position as completely equal, not surprising given its symmetry.} 26. Bc2 Kg8 27. Qd3 Kf7 {Black decides to get her king closer to the center before offering an exchange of queens.} 28. Qe4 Qg4 29. Qxg4 Bxg4 { somewhat paradoxically, with the queens off it makes it more difficult for White in practical terms. Now Zatonskih gives a lesson in how to play bishop endings.} 30. Kf2 Kf6 31. Bd3 g5 32. Bf1 {this withdrawal allows Black to immediately seize a key diagonal.} Bf5 33. Be2 Be4 34. h3 b5 {a provocative move that appears to have rattled her opponent.} 35. b3 (35. cxb5 Bxd5 36. b3 { and now Black cannot penetrate on the queenside.}) 35... b4 36. Bd1 Bb1 { the move that seals White's fate.} 37. Bc1 Bxa2 38. Bc2 a5 39. Bb2 Be5 40. Bd1 a4 41. bxa4 Bxc4 42. Bf3 d3 43. Bc1 b3 0-1

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