Sunday, January 17, 2010

Dividing Line

Instructional books will tell you that an advanced pawn may become weak in an endgame. But in the middlegame, it is a different story. A strong advanced pawn can cut the enemy position in two, and defending pieces are of little use if they cannot reach the
threatened sector.

An example is Richter-Engels, Bad Saarow 1937:

1. e4 c5 2. Nf3 d6 3. Be2 Nc6 4. d4 cxd4 5. Nxd4 Nf6 6. Nc3 g6 7. 0-0 Bg7 8. Be3 0-0 9. Qd2

White commits himself to giving up one of his Bishops for a Knight, but he will gain time to begin his attack.

9. ... Ng4 10. Bxg4 Bxg4 11. f4

White threatened 12. f5, followed by 13. h3 and 14. g4, trapping the Bishop.

11. ... Bd7 12. Rad1 Rc8 13. Qf2 Na5 14. f5 Nc4 15. Nd5 Nxe3

Two Knights against two Bishops, and in an open position -- but the Knights have taken up strong posts in the center, and they will not be easy to dislodge.

16. Qxe3 Re8

Black cannot afford to go pawn-hunting with 16. ... Bxd4 17. Rxd4 Rxc2, since 18. Qh6! sets up the dual threats of 19. Nxe7+ Qxe7 20. f6, and 19. e5 followed by 20. Rh4. A bit better than the game would be 16. ... e6, but White has a big edge after 17. f6 exd5 18.
fxg7 Kxg7 19. exd5.

17. Qf2 e6 18. Ne3 Kh8 19. f6 Bf8 20. e5!

White wants to bring his Knight from d4 to g5 via f3, without losing the f6-pawn. With the opening of the d-file, the White Rook joins the battle, and the Black Queenside pieces will be spectators for the rest of the game.

20. ... dxe5 21. Nf3 Qc7 22. Ng5 Kg8 (diagram) 23. Nxh7!

White begins an elegant mating combination, based on the thorn at f6.

23. ... Kxh7 24. Qh4+ Kg8 25. Rf3!

Black is defenseless against the threat of 26. Rh3 and 27. Qh8 mate.

25. ... Bg7 26. Rh3 Kf8 27. Qh8+ Bxh8 28. Rxh8+ mate.

No comments: