10 February 2013

Annotated Game #82: A good diagnosis

This recent game (part of the Chessmaster ladder series of training games) provided a good diagnosis of my current playing strengths and weaknesses.  The opening phase is strong, with my opponent following a move 8 sideline of the Caro-Kann Panov variation (officially classified as a Queen's Gambit Declined Semi-Tarrasch, which is what it becomes via transposition).  White's strategic error on move 11 with the bishop exchange gives Black relatively easy equality, in contrast with the kingside pressure White normally achieves in this variation.

The early middlegame analysis (moves 12-14) shows some interesting alternative plans for Black.  This for me is often the most valuable part of these training exercises.  Knowing how to play the early middlegame positions, in other words having a good idea of what to do in a position after your opening lines are finished, is a crucial skill and is something that I have often failed to do well.  In this game, my chosen path was not bad, but being aware of the other opportunities in the position will give me an advantage the next time I play a similar middlegame.

The game becomes tactical on move 17 as White drops a pawn with a typical computer handicap move.  However, it was much more interesting than it appeared, as the chosen method of White's piece recapture would have allowed Black to eventually win White's queen with a back-rank pin or check.  This was not obvious, however, and I instead focused on winning the pawn.

By move 24 we have an endgame where Black could have achieved a significantly stronger position by exchanging pawns on f3, inflicting a weakened structure on White and maintaining a strongly supported d-pawn.  Black instead ends up with several weak, isolated pawns that he cannot defend adequately, but is able to capture White pawns in exchange for them.  Black is stopped during the final race on the kingside, where the 2-to-1 pawn advantage is not enough to win in the single minor piece (BvN) endgame.

Diagnosis summary:
  • Solid opening preparation
  • Early middlegame was OK but not optimal, but this is not surprising given my lack of experience with actually playing the position.
  • Although I did not see the full possibilities of 18...Bf4! in terms of trapping the queen several moves later, I at least considered it as a candidate move, which I would not have done previously.
  • Remaining middlegame play was good, including the decision to force an exchange of queens and transition to the endgame.
  • I used my thinking process reasonably well and did not miss any significant threats from my opponent.
  • First endgame strategic decision was incorrect (not exchanging on f3), leading to better chances for my opponent.
  • Later on, my endgame advantage may not have been enough to win against best play, but I passed up several chances to improve my situation.
  • I lack knowledge of correct strategies in BvN endgames.

[Event "Chessmaster: Grandmaster Edition Rated G"] [Site "?"] [Date "2013.02.09"] [Round "?"] [White "Josh - Age 8 (CM Class B)"] [Black "ChessAdmin"] [Result "1/2-1/2"] [ECO "D41"] [Annotator "ChessAdmin/Houdini"] [PlyCount "119"] [EventDate "2012.??.??"] [TimeControl "3600+10"] {D41: Queen's Gambit Declined: Semi-Tarrasch with cxd5} 1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 e6 6. Nf3 Be7 7. cxd5 Nxd5 {a position common to the Semi-Tarrasch defense has now been reached.} 8. Bc4 {Bd3 is more usual here.} O-O 9. O-O Nc6 (9... Nxc3 10. bxc3 Qc7 {is an interesting-looking alternative.}) 10. Re1 a6 {end of my personal book. Black has a number of other possibilities here, including ...Bf6.} 11. Bxd5 {Black should be able to better exploit the advantage of the two bishops after this, although the symmetrical pawn structure gives the position a drawish characteristic.} ({ Here's a more classic example of play:} 11. Bd3 Ncb4 12. Bb1 b5 13. a3 Nxc3 14. bxc3 Nd5 15. Qd3 Nf6 16. Bg5 g6 17. Ne5 Bb7 18. Qh3 Bd5 19. Ba2 Rc8 20. Bh6 Re8 21. Bxd5 Qxd5 22. Bg5 Nh5 23. Bd2 Nf6 24. a4 Ne4 25. Qd3 Nxd2 {Uhlmann,W (2555) -Pachman,L (2520) Manila 1976 1/2-1/2 (41)}) 11... exd5 {Black has the pair of bishops.} 12. Ne5 (12. Qb3 {appears the most threatening, but Black has} Bg4 { as an effective countermove.} 13. Qxd5 Bxf3 14. Qxf3 Qxd4 15. Be3 Qh4 16. Nd5 Bd6 17. g3 Qh3 18. Rad1 Be5 19. b3 Rfe8 20. Bf4 Bxf4 21. Nxf4 Rxe1+ 22. Rxe1 Qd7 23. Qd5 Qxd5 24. Nxd5 Kf8 25. Kg2 Re8 26. Rxe8+ Kxe8 27. Kf3 Kd7 28. Ke4 Kd6 {1/2-1/2 (28) Osnos,V-Krogius,N Budapest 1965}) (12. h3 {applies prophylaxis to the ...Bg4 idea, but then Black has time to shore up his position.} Be6 13. Bf4 Bf6 14. Qd2 b5 15. Rad1 Re8 16. Bg5 Nxd4 17. Nxd4 Bxg5 18. Qd3 Qd7 19. b4 Be7 20. a3 Rac8 21. Nce2 Bf6 22. Nb3 Bf5 23. Qg3 Bc2 24. Rc1 Bxb3 25. Rxc8 Qxc8 26. Qxb3 Qc4 {Moliboga,V-Lyrberg,P (2425) Duisburg 1992 0-1 (32)}) 12... Bf6 {first major decision point. Also considered Re8 or exchanging on e5, which are Houdini's top two choices.} (12... Nxe5 13. dxe5 d4 14. Ne4 Bf5 {is the most active option.}) (12... Re8 13. Nxc6 bxc6 14. Bf4 Bf5 {is similar to the game continuation, but with some additional breathing room for Black.}) 13. Nxc6 bxc6 {this pawn structure didn't bother me too much, since I didn't think White could exploit the weakness of the c-pawn and it reinforces the d5 pawn well. The a-pawn is also weakened now, however.} 14. Bf4 {taking advantage of Black's 12th move, since the bishop cannot be easily challenged.} Re8 {played with the idea of exchanging rooks, to take advantage of the fact that the White queen is the next piece in line, so White cannot immediately seize the e-file.} (14... Qb6 {is the more active-looking choice, with threats to the d4 and b2 pawns. White would now be able to penetrate with the bishop on d6, however.} 15. Bd6 Rd8 16. Bc5) (14... a5 {is an interesting idea which I considered at various points, prmarily with the thought of developing with ...Ba6. Houdini likes it because ofthe possibility of developing with ...Ra7-e7.}) (14... Bg5 $6 15. Bxg5 Qxg5 16. Re5) 15. Rxe8+ Qxe8 16. Qd2 Bf5 {I decided getting the bishop out was most important at this point.} 17. Be5 {a typical computer handicap move.} (17. Re1 {is what I had expected.} Qd7) 17... Bxe5 $15 18. Re1 $2 {at the time, I thought that this move pinning the bishop would amount to the same thing as the immediate recapture, with White losing a pawn.} (18. dxe5 Qxe5 19. Re1) 18... f6 { the other option for winning a pawn is ... Bxh2+. I chose this move instead because of the strong center and passed d-pawn that would result.} (18... Bf4 $1 {is the win seen by Houdini. I did actually look at this variation in my calculation of candidate moves, but not far enough.} 19. Rxe8+ Rxe8 $19 { at this point I saw that the Bf4 could not be taken due to the back-rank mate threat, but otherwise thought that the material was roughly equal and would not bring Black an advantage. However, Black can keep challenging the White queen based on the back-rank mate and gain a winning advantage. For example} 20. Qd1 Bc2 21. Qf1 Bd2 {and White cannot avoid the back-rank threat to his queen.}) 19. dxe5 $15 fxe5 20. Qg5 (20. Qe2 Rd8 $15) 20... Qe6 21. Na4 { the obvious plan to take advantage of the c5 hole and also pressure the a-pawn. } e4 22. Nc5 Qg6 {essentially forces an exchange, since Black would threaten .. .Bh3 after a retreat off the g-file.} 23. Qxg6 Bxg6 24. f3 {this marks the beginning of the endgame phase. I should have exchanged on f3, with a superior structure as a result.} Re8 (24... exf3 25. gxf3 Kf7 26. Nd7 $15 Rc8) 25. fxe4 $11 (25. Nxa6 $2 {would be too greedy.} e3 26. Nc5 d4 $19) 25... dxe4 { compared to the line in the variation, Black now has three weak pawns in the center and queenside and White will be able to stop the isolated passed e-pawn. } 26. Nxa6 {I had anticipated this and thought it simply helped Black's cause by breaking up White's pawns on the queenside in return.} Ra8 27. Nb4 c5 28. Nc6 Rxa2 29. Rf1 {threatening a back-rank mate after Ne7+} h6 30. Ne5 Be8 31. b3 Rb2 {Black threatens to win material: Rb2xb3} 32. Nc4 (32. Re1 Rxb3 33. Rxe4 Bb5 $15) 32... Rxb3 $17 {the position at first glance looks great for Black, but he will inevitably lose one of the pawns.} 33. Re1 Bb5 34. Rxe4 Rb4 35. Nd6 Rxe4 36. Nxe4 c4 37. Kf2 Kf8 38. Ke3 Ke7 (38... Bc6 {I find this idea later, but it should have been played sooner.} 39. Kd4 $17) 39. Kd4 (39. g3 {is how White could avoid losing the g2 pawn.} Bc6 40. Nf2 Bd5 $11) 39... Bc6 $17 40. Nd2 Bxg2 41. Nxc4 Kf6 42. Nd6 g5 43. Nc4 g4 {a premature advance of the unsupported g-pawn.} (43... h5 $5) 44. Ne5 $6 (44. Ke3 $5 $11) 44... Kf5 $17 { I had been hoping for this after the g4 push.} 45. Nf7 h5 46. Ne5 $2 {Houdini immediately sees a huge advantage for Black now.} (46. Ke3 Bc6 $17) 46... Kf4 ( 46... h4 47. Nd3 Bf1 48. Ne5 $19 Kf4 49. Ng6+ Kg5 50. Ne5 Kf5 {White's king now cannot move back to help stop the Black pawns without abandoning the knight, while any knight move will allow Black to push ...g3.}) 47. Nd3+ $2 { this would allow Black to make progress with the king.} (47. Ng6+ Kg5 48. Ne7 h4 $17) 47... Kg5 {here I became too conservative.} (47... Kf3 {is clearly better.}) 48. Ke3 (48. Ke5 Bb7 $15) 48... Bf1 {this limits the bishop's mobility too much.} 49. Nc5 Kh4 {what I had intended after the 47th move, although it is obvious that White is now in a much better position to defend.} 50. Kf4 Kh3 {this is now a draw.} (50... Bc4 51. Ne4 $15) 51. Ne4 $11 {one of Black's pawns will now fall in exchange for the h2 pawn. White can then sacrifice the knight for the other pawn if required.} Be2 52. Ng3 Bf3 53. Nxh5 Kxh2 54. Nf6 g3 55. Kxf3 g2 56. Ng4+ Kh1 57. Nf2+ Kh2 58. Ng4+ Kh1 59. Nf2+ { Twofold repetition} Kh2 60. Ng4+ 1/2-1/2

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