Friday, May 15, 2009

Sacrificing the Queen for Two Minor Pieces (Part 2)

Ehlvest goes berserk! Nakamura's queen sacrifice in the second round of the U.S. Championships must have made a strong impression on his opponent, Jaan Ehlvest. A mere, three rounds later Ehlvest himself sacrificed his queen for bishop and knight against Varuzhan Akobian. Unfortunately for Ehlvest, his moment of inspiration did not work out very well.

1. e4 e6 2. d4 d5 3. Nd2 Nf6 4. Bd3 c5 5. e5 Nfd7 6. c3 Nc6 7. Ngf3 Qb6 8. O-O cxd4 9. cxd4 Nxd4 10. Nxd4 Qxd4 11. Nf3 Qb6 12. Qa4 Qb4 13. Qc2 Nc5 14. Bd2 Qa4 15. b3 Qd7 16. Nd4 Qd8 17. Rac1 Bd7 18. Be2 Ne4 19. Nb5 Bc5

Ehlvest has sacrificed a pawn in a French Tarrasch, but does not appear to have much compensation in this position. The only thing he really has going for him is that Black's king is still in the center. White's knight is ready to harass the king from d6, but Black's dark-squared bishop and knight are both covering that square. But how can White deflect them from the defense of d6? 20. Be3 seems like a plausible move. There are then a lot of potential variations to evaluate:

a. 20...a6? 21. Bxc5 Bxb5 22. Bxb5+ axb5 23. Bb4 gives White a nice advantage, with the Black king stuck in the center, strong dark-square control, and the Black knight in danger of being trapped.

b. 20...Rc8 21. Bxc5 Rxc5 22. Nd6+ Kf8 23. Qb2 Rxc1 24. Rxc1 Nxd6 25. exd6 Bc6 26. Qe5 and White has good compensation for the pawn, because Black's rook isn't in play.

c. 20...Bxe3 21. Nc7+ Ke7 22. fxe3 Rc8 23. Bd3 Bc6 24. Bxe4 Qxc7 (24...dxe4?? allows 25. Qc5+ Kd7 26. Qd6 mate!) 25. Bd3 Qxe5 26. Qc5+ Ke8 27. Qxa7 seems unclear. Black is up a pawn but his king is stuck in the center. White queen is off-side while Black's is nicely centralized. White also has to watch out for his king's position.

In any event, 20. Be3 seems playable, although there were a lot of complicated variations to evaluate. Ehlvest's way of breaking through to the d6 square is more elegant:

20. Qxc5?!?! Nxc5 21. Nd6+ Ke7 22. Rxc5

What does White have for the queen? Materially, a bishop and a knight, though White is also a pawn down. Black's king is stuck in the center, White's knight is an octopus in the middle of the board at d6, and Black is weak on the dark squares. It doesn't seem like enough and, in the rest of the game, Akobian calmly defends and brings home the full point. But, as we will see, Ehlvest might have had a chance or two to make things messier.

As an aside, we are dealing here with a very different kind of sacrifice from those seen in Spassky-Bronstein or even Ehlvest-Nakamura. In those games, Black's compensation was largely material and structural. Here, Ehlvest's compensation is based on his temporary initiative against Black's weakened king. If he doesn't break through soon, he will be lost. It is thus actually an older style of sacrifice. For example, the oldest example in my database of the material imbalance Queen + Two Rooks + Two Minor Pieces vs. Two Rooks + Four Minor Pieces is the following game:

1. d4 d5 2. c4 dxc4 3. e4 e5 4. d5 f5 5. Nc3 Nf6 6. Bxc4 Bc5 7. Nf3 Qe7 8. Bg5 Bxf2+ 9. Kf1 Bb6 10. Qe2 f4 11. Rd1 Bg4 12. d6 cxd6 13. Nd5


Black, already up two pawns, sacrifices his queen for bishop and knight. He also gets a knight on e3 and White's king is stuck in the center. I won't comment on the rest of the game, except to point out how Black repeatedly eschews chances to win back material in favor of pursuing his initiative (16...Rd8 instead of 16...Nxd1; 19...Rac8 instead of 19...Nxg2+; 20...b5 instead of 20...Bxd2+).

14. Bxe7 Ne3+ 15. Ke1 Kxe7 16. Qd3 Rd8 17. Rd2 Nc6 18. b3 Ba5 19. a3 Rac8 20. Rg1 b5 21. Bxb5 Bxf3 22. gxf3 Nd4 23. Bc4 Nxf3+ 24. Kf2 Nxd2 25. Rxg7+ Kf6 26. Rf7+ Kg6 27. Rb7 Ndxc4 28. bxc4 Rxc4 29. Qb1 Bb6 30. Kf3 Rc3 31. Qa2 Nc4+ 32. Kg4 Rg8 33. Rxb6 axb6 34. Kh4 Kf6 35. Qe2 Rg6 36. Qh5 Ne3 0-1

A marvelous game. Incidentally, in Part 3 I will discuss a couple of games by Larsen and Tal that also feature Nxd5 followed by Ne3 as the key moves in a sacrifice of queen for two minor pieces.

Back to Ehlvest-Akobian.


This may not have been the best move. Engines favor 22...b6 or 22...Kf8. After the move in the game, Ehlvest seems to have missed a strong move.

Here Ehlvest could have played 23.Bb4! This move highlights Black's weakness on the dark squares and his stalemated king. The position is incredibly complicated.

The concrete idea behind Bb4 is to make Nxb7 more of a threat, because it sets up a powerful discovered check on the next move. For example, if 23...h6 24. Nxb7 Qb8 25. Rxd5+ Kf7 26. Rxd7+ and White is winning.

So Black should play something like 23...Qb6, covering b7 and attacking the bishop. White can then play the computer move 24. Rb5!?, when after 24...Bxb5 25. Bxb5 Black can't prevent Nc8+, winning back the queen. The resulting rook and two bishops versus two rooks ending looks safe for White. Better for Black is therefore 24...Qa6, when White doesn't have any effective discovered checks. White's best might be 25. Nc4+ Kf7 26. Rxd5 (setting up the following discovered attack on the queen) exd5 27. Nd6+ Qxd6 28. exd6, but then Black is up a clean exchange. If this analysis is correct (and it probably isn't), then White's sacrifice was unsound, although this line would have made things much harder for Black than the game continuation.

23. Rfc1 fxe5!

Akobian offers to return the queen.

24. Nxb7

White's initiative leads to nothing after this move, but the alternative 24. Bg5+ Kxd6 25. Bxd8 Raxd8 just leads to a lost ending down two pawns.

24...Qb6 25. Bg5+ Ke8 26. Rc7 Rb8 27. Bb5 Rxb7 28. Bxd7+ Kf7 29. Be8+ Kxe8 30. Rc8+ Kf7 31. Rxh8 h6 32. Bh4 Rc7 33. Rf1 Rc2 34. Bg3 Qc7 35. h4 d4 36. Kh2 d3 37. f4 Qc6 38. fxe5+ Kg6 39. Bf2 d2 40. Rd8 Rc1 0-1

Cool-headed defense from Akobian that put him in a tie for first after the round.

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