13 November 2013

Commentary - 2013 Russian Championship (Women's Round 4)

As I mentioned a while ago, I am continuing to work on commentary for several international games that caught my eye over the past month.  This next game, from round 4 of the women's section of the Russian championship played in October, features the sacrificial 3...c5 line of the Caro-Kann.  Alexandra Kosteniuk employs it well and the game is complex both tactically and positionally; the original ChessBase report mentioned that it was a "very strange game", which is difficult to deny, which of course also makes it very interesting.  Among other things, multiple pawn sacrifices are offered, refused and finally accepted.  Tatiana Kosintseva missed (or deliberately passed up, hard to say) more than one chance to force a draw and seemed to be pressing at the end as well, but overextended herself and allowed Black to win the ending.

[Event "63rd ch-RUS w 2013"] [Site "Nizhny Novgorod RUS"] [Date "2013.10.08"] [Round "4.2"] [White "Kosintseva, Tatiana"] [Black "Kosteniuk, Alexandra"] [Result "0-1"] [ECO "B12"] [WhiteElo "2515"] [BlackElo "2495"] [Annotator "ChessAdmin/Houdini"] [PlyCount "130"] [EventDate "2013.10.05"] 1. e4 c6 2. d4 d5 3. e5 c5 4. c3 {less challenging than taking on c5, but of course solid for White. This move is frequently seen at the Class level.} Nc6 5. Nf3 Bg4 {this is essentially Black's ideal setup out of this variation and the database statistics show it, as Black scores close to 63 percent.} 6. dxc5 {Kosintseva has played this frequently, including a prior game against Kosteniuk from earlier this year in May. Black therefore must have had the expectation that White would enter this line. The capture is usually made on move 4 when first possible; this variation can be reached alternatively by White playing the capture and following up with 6. c3, which however is not the most aggressive continuation.} a6 $146 {a novelty on move 6! However, perhaps not so unusual when it's one of Houdini's top choices. The move also appears in their previous game, at a later point. Here it helps restrain the idea of White pushing the b-pawn.} (6... e6 {is what Kosteniuk played before and is most common.} 7. b4 Bxf3 8. Qxf3 Qc7 9. Bf4 a6 10. Nd2 g5 11. Bg3 Nge7 12. Bd3 Bg7 13. Qe3 h6 14. f4 gxf4 15. Bxf4 d4 16. cxd4 Nd5 17. Qf2 Nxf4 18. Qxf4 O-O-O 19. Nf3 Nxd4 20. O-O Nxf3+ 21. Qxf3 Bxe5 22. Rad1 Bxh2+ 23. Kh1 Rd4 24. Be4 Rhd8 25. Bxb7+ Qxb7 26. Qxb7+ Kxb7 27. Rxd4 Rxd4 28. Kxh2 Rxb4 29. Rxf7+ Kc6 30. Rf6 Re4 31. Rxh6 Kxc5 32. Rh3 Re2 33. Ra3 Kb5 34. Kg3 a5 35. Kf3 Rc2 36. g4 a4 37. g5 Kb4 38. Re3 Rxa2 39. g6 Rd2 40. Rxe6 Rd7 41. Kf4 a3 42. Ra6 Kb3 43. Rb6+ Kc2 44. Rc6+ Kb3 45. Rb6+ Kc2 46. Rc6+ {1/2-1/2 (46) Kosintseva,T (2517)-Kosteniuk,A (2491) Geneva SUI 2013}) 7. Be3 Bxf3 {this "little tactic" was of course foreseen by White. In other lines with an earlier dxc5, White may try to hang on to the extra pawn. Here white cedes the e5 pawn, but in exchange gets the two bishops.} 8. Qxf3 Nxe5 9. Qd1 {White evidently wants to keep her options open regarding future placement of the queen.} e6 10. Be2 Ne7 {in this French-type structure, the knight development with Ne7-f5 is both common and effective.} 11. b4 {reinforcing c5 and untying the Be3 from the pawn's defense.} Nf5 12. Bf4 Nc6 {by this point Black has comfortable equality, with a dynamic balance between the minor pieces and pawn structures. Black's position looks more natural to play, although there is no real advantage.} 13. O-O g6 (13... Be7 {is also possible, with the idea of exchanging off the Bf4.}) 14. Bd3 {the bishop was accomplishing nothing on its previous diagonal and has limited scope, given Black's pawn structure, so now it is going to exchange itself off.} Bg7 15. Bxf5 gxf5 {this looks like a strange line for Black to enter, but a similar structure can occur, for example, in the Caro-Kann Exchange Variation. Black argues that the possibility of using the open g-file and stronger central pawn structure outweigh the weakening of the kingside.} 16. Bd6 a5 (16... Bf8 {is Houdini's preference, seeking to exchange the Bd6 or drive it away.}) (16... Nxb4 17. Re1 Qd7 {is an interesting possibility; the c3 pawn cannot capture, as it is pinned to the Ra1. Black cannot hold onto the pawn (the d5 pawn can be captured once the knight moves, due to the pin on the e6 pawn), but it would be another way to disrupt White's queenside pawns. Play could continue} 18. a4 Rg8 19. g3 a5 20. Ra3 Na6 21. Qxd5 O-O-O $5) 17. bxa5 {this seems to be exactly what Black wanted.} (17. b5 {it is unclear to me why White would not prefer this to the text move, as it mobilizes the queenside pawn majority to good effect.}) 17... Rxa5 18. Nd2 {evidently heading for b3 to help protect c5. White offers the c3 pawn in the process.} Qd7 (18... Bxc3 {leads to complicated play.} 19. Rb1 b5 20. a3 (20. cxb6 Qxd6 21. Nc4 Qc5 22. Nxa5 Qxa5 23. a4 $15) 20... Qa8 {and Houdini evaluates this as equal, but there is a lot going on for both sides here.}) 19. Nb3 Ra4 {a master-level move, keeping the rook advanced and mobile along the open fourth rank.} 20. Nd2 Ra3 21. Rb1 Be5 { Black finally decides to exchange off the bishop.} 22. Bxe5 Nxe5 23. Re1 Ng6 ( 23... Nd3 24. Re3 Nxc5 25. Nb3 Nxb3 26. axb3 O-O {is evaluated as equal by the engine.}) 24. Qc1 {perhaps with the idea of exploiting the c1-h6 diagonal, although this does not happen in the game.} (24. Nf3 $5) 24... Rxa2 {Black now decides to take one of the pawns offered to her.} 25. Nf3 O-O 26. h4 f6 $6 { this covers g5 and e5, but weakens e6 at the same time.} (26... Qc7 {instead seizes a key diagonal and allows Black to make some threats.}) 27. Rb6 { White fails here to put Black under maximum pressure, allowing her to strengthen the center.} (27. h5 {would be the most testing move.} Ne7 28. Rb6 Nc6 29. Nd4 Re8 30. Qb1 Ra7 31. h6) 27... e5 {although the earlier ...f6 may not have been fully accurate, the text move is now possible.} 28. Qb1 Ra7 29. Rd6 Qc8 30. Rxd5 Ne7 31. Rd6 Qxc5 {the position has simplified now and is equal, with Black's small material plus offset by the weaker pawn structure (3 pawn islands versus 2) and White's piece activity.} 32. Qb3+ Kh8 (32... Kg7 $2 33. Rd7) 33. Rd7 Ng6 34. Qe6 b5 {going for further simplification, at the cost of one of Black's doubled pawns.} 35. Rxa7 Qxa7 36. Qxf5 Qg7 (36... Qf7 { would neutralize a possible h5 push.} 37. h5 Nf4 38. Re4 Nxh5 39. Rh4 Nf4 40. Nxe5 fxe5 41. Rxh7+ Qxh7 42. Qxf8+ Qg8 {and White takes a perpetual check.}) 37. Rd1 (37. h5 {again would challenge Black most effectively.}) 37... Nf4 38. g3 Ne2+ 39. Kg2 Qg6 40. Qxg6 hxg6 {Houdini considers this an equal endgame, although Black has a small advantage based on her knight's activity.} 41. Rd7 Nxc3 42. Rb7 (42. Rc7 Ne4 43. Rb7) 42... Kg8 (42... Rd8 $5) 43. g4 {White seems to be overpressing on the kingside and creating potential weaknesses.} Rd8 44. h5 g5 45. Nh2 $6 {this appears to needlessly let Black's rook onto the fourth rank.} (45. Rb6) 45... Rd4 $17 46. f3 Rd2+ $11 (46... e4 {is what Houdini prefers.} 47. fxe4 Rxe4 48. Kf3 Rf4+ 49. Ke3 b4 $17) 47. Kh1 {forced.} (47. Kg1 $2 Ne2+ {and now the knight and rook combine to penetrate the kingside, for example} 48. Kg2 Nf4+ 49. Kg1 Rg2+ 50. Kh1 Rg3 51. Rb8+ Kg7 52. Rb7+ Kh6 53. Rxb5 Nh3 54. Nf1 Nf2+ 55. Kh2 Rxf3) 47... Rb2 48. Nf1 e4 49. fxe4 Nxe4 50. Ne3 (50. Kg1 $5) 50... Rb3 51. Nd5 Nf2+ 52. Kg1 Nxg4 {White's weakening pawn advance is finally exploited by Black.} 53. Ne7+ Kf8 54. Nf5 ( 54. Kg2) 54... Rh3 (54... Rb2) 55. h6 $6 {not sure what White's intent was here.} (55. Rxb5 Rxh5 56. Rb8+ Kf7 57. Rb7+ Kg6 58. Ne7+ Kf7 59. Nf5+ {and Black cannot escape the checks, due to the knight fork on g7.}) 55... Nxh6 56. Kg2 g4 57. Nd4 {Houdini shows a win for Black now.} (57. Rxb5) 57... Re3 58. Kf2 Re4 59. Nxb5 Rb4 60. Rh7 Rxb5 61. Rxh6 Kg7 {unlike in the move 57 variation, White's rook now cannot attack Black's pawns and king from the side, making the defense impossible.} 62. Rh4 f5 63. Kg3 Kg6 64. Rh8 Rb3+ 65. Kg2 Kg5 0-1

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