30 January 2014

Annotated Game #114: A speculative "sacrifice"

This game was the next game played on Chess.com after Annotated Game #113 and made me wonder if my opponent had looked that up and copied the Exchange Variation, simply because White had won the previous game that way.  In any case, the game diverges early (move 6) and Black achieves a more standard position in the line than in the other game, easily equalizing.

After mishandling a combinational idea (see move 15), which resulted in what I thought was a rather stale-looking position, I decided to undertake a speculative "sacrifice" on move 18.  Black nets three pawns for the knight, so it's not technically a material deficit, but Black still feels the loss of the piece before the pawns can mobilize effectively.  Despite some additional pressure that I also obtained from placing a rook on the second rank, my opponent defended well and I decided to try and head for the endgame, where I felt with my extra pawns I would have an edge and all the real winning chances.

Unfortunately there was still enough material on the board for White to be able to gain the initiative and pose some threats - to which I reacted poorly, making what should have been a losing blunder on move 27. The seesaw battle after that was not well played by either of us, but as Tartakower said, the winner of the game is the player who makes the next-to-last mistake.  I felt a little personally redeemed at the end of the game, since I correctly calculated a sequence involving a pawn sacrifice that ensured White could not prevent one of my central pawns from queening.

I learned a good deal from this game and did some rare things for me as a player (the knight "sacrifice" and finding an endgame combination), so despite the panic and poor play for a series of moves I'll chalk it up as a positive experience in general for my chess.

[Event "DHLC Slow Swiss #11"] [Site "Chess.com"] [Date "2014.01.26"] [Round "5"] [White "Okieman888"] [Black "ChessAdmin_01"] [Result "0-1"] [ECO "B13"] [WhiteElo "1365"] [BlackElo "1470"] [Annotator "ChessAdmin/Houdini"] [PlyCount "68"] [EventDate "2014.??.??"] [TimeControl "45"] 1. e4 c6 2. d4 d5 3. exd5 cxd5 4. Bd3 Nc6 5. c3 Nf6 6. Nf3 {normal is Bf4 or Bg5 as an alternative.} Bg4 {I thought for a little while here and decided that this made the most sense as a reaction to White's move-order. It is a standard move anyway in the variation.} 7. O-O e6 {by this point Black already has comfortable equality.} 8. Bg5 h6 {provoking the exchange. I thought that the dark-square bishop would be better placed on d6 than it would after Be7, which the database shows is the standard move in the position.} 9. Bxf6 Qxf6 { with the queen in place, now Black can think about exchanging off the Bd3 without ruining his pawn structure.} 10. Nbd2 (10. Qb3 {might challenge Black a little more, at least removing the queen from the kingside.} Qe7 11. Nbd2 g6 $11) 10... Bd6 11. Re1 O-O 12. Qb3 Rab8 {I didn't see anything better here. Although the rook is tied to the defense of the b-pawn, White's queen isn't doing a whole lot more. Houdini agrees.} 13. h3 Bf5 14. Bf1 {this was a bit of a surprise, although the bishop does play a defensive role here. Rarely does White let Black get dominance of the h7-b1 diagonal and it gets used in this game to good effect later.} Rfc8 {this is intended to activate the rook and shore up Black's queenside against potential breaks on the c-file.} 15. Nh2 $6 {seemingly intending Ng4 or Nbf3, but neither seem to be particularly effective maneuvers for White. However, with my next move I turn it into a smart idea for White.} Bxh2+ $6 {dubious for both the reason played (calculation of a flawed combination) and for the positional blunder of exchanging a beatiful, unopposed dark-square bishop for a knight on the rim.} ( 15... Bxh3 $1 {is the correct version of the combination, taking advantage of the weakness of f2 and the hanging Nd2.} 16. Ndf3 (16. gxh3 $2 Bxh2+ 17. Kxh2 Qxf2+) 16... Bf5) 16. Kxh2 Qh4 (16... Bxh3 $2 {was what I had originally calculated, only considering the pawn recapture, which would then allow for ... Qxf2+ and then taking the unprotected Nd2. Luckily I actually rechecked the move and falsified it, as} 17. Kxh3 {refutes the idea.} Qf5+ 18. g4 Qxf2 19. Qd1 $16) 17. g3 {After Black's last move, White apparently saw the renewed threat of ...Bxh3.} Qf6 18. Qd1 {now the Nd2 is no longer hanging.} Nxd4 $5 { I thought for a while here and calculated that I could get three pawns and some pressure for the piece, along with a dominant center. In part I simply wanted to see if the idea would work for my own edification, while also not seeing any other useful alternate plans for Black.} (18... b5 {followed by ... b4 is Houdini's preferred plan, the idea being to undermine support for the d4 pawn.}) 19. cxd4 Qxd4 20. Kg2 {White thought a while over this, choosing to save the f-pawn.} Rc2 {I thought for a little while here, considering the rook move would cause much more difficulty for White than simply snatching the b2 pawn.} 21. Re2 {White thought for a good length of time here and defends correctly with the only move.} Qxb2 (21... Bd3 {I calculated would not work because of} 22. Nf3 {and now the Bd3 is pinned while White attacks both the Qd4 and the Re2.} (22. Nb3 {is even much better for White.})) 22. Nf3 {White has avoided the major threats and I felt it was best to start exchanging material and heading for an endgame, where Black's extra pawns (especially the protected passed d-pawn) should give him a significant edge.} Rxe2 23. Bxe2 Be4 {I thought at the time that it was best to immobilize the Nf3, at least temporarily, but ...Rc8 in hindsight looks much better (Houdini agrees), as the Rb8 contributes little to the fight, a crucial deficit at a time when Black is trying to contain White's pieces.} 24. Rc1 a6 {with the idea of cramping White's bishop and making the pawns less vulnerable to a White rook on the 7th rank.} 25. Rc7 Qxa2 {I felt afterwards that this was greedy and it nearly cost me the game, as White now gets a strong initiative. Houdini considers it objectively best, however.} 26. Bd3 {a strong move, as it eliminates a key Black piece and will open up lines in a dangerous way for White's queen.} Qa5 {I rush to bring my queen back into the defense. Unfortunately, the queen is still not well placed.} 27. Rd7 f5 $2 {at the time this idea seemed like the only way to hold the positon together and I was feeling some time pressure so went ahead and played it without sufficient calculation. In fact it should lose, as it fatally undermines Black's center and exposes the king.} (27... Qc3 {there was no need to get panicky and play the text move, as something relatively simple like this will keep Black equal.} 28. Bxe4 dxe4 29. Nd4 Qc8 $11) 28. Bxe4 fxe4 29. Ne5 $2 (29. Qd4 {and now White has a mate in 6, as g7 cannot be defended.}) 29... Rd8 $2 {this superficially looks helpful but in fact simply weakens Black's position.} ( 29... Qc3 $16) 30. Rxb7 $18 (30. Nc4 $1 {is even better.} dxc4 31. Rxd8+) 30... d4 $2 {the point of the rook being on d8, to allow the advance of the pawn with a discovered attack on the Ne5. However, I completely missed the possibility of a fork with Nc6, probably because I had not properly considered (visualized) the position of the Qa5 in relation to the rook; I very rarely have a queen in that spot in my games. My opponent mentioned afterwards that he saw the fork, but thought that the text move would be more effective.} 31. Qg4 $2 (31. Nc6 $18) 31... Qxe5 $19 {the only move, covering g7 (and winning for Black). I had a bad moment here during the game, as the text move seemed crushing, but then I perceived that the queen would in fact protect against the mate. I attribute the difficulty to the well-known problem of sometimes missing "backwards" moves by pieces.} 32. Rb6 e3 {I spent a fair amount of time here to calculate the forced continuation into a winning endgame. Finally the pawns that Black sacrificed for come into their own!} 33. Qxe6+ Qxe6 34. Rxe6 d3 {now White cannot stop one of the pawns from queening.} 0-1

1 comment:

  1. A knight is a little more than 3 Pawns ( Knight = 3.5 Pawns for human players ) but 2 of these pawns have been centerpawns and you did get a protected passer too.
    http://home.comcast.net/~danheisman/Articles/evaluation_of_material_imbalance.htm

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