Tuesday, December 28, 2010

Material Imbalances

Submitted by WGM Natalia_Pogonina on Tue, 12/28/2010 at 1:01am.
From the very first steps in chess we learn the average value of the pieces. A queen is worth about two rooks, bishop and knight – about 3 pawns. Of course, it is an approximation. Chess is a very complex game, so quite often imbalances occur. Three pawns may suddenly overcome a rook, two pieces – beat a queen, and so on. One cannot rely on the standard values of the pieces only. The position plays a serious role too. All the above-mentioned refers not to short-terms tactics which lead to winning back the sacrificed material or mate, but to a long-term game with a material imbalance.
The most typical cases of material imbalances are:

1) Sacrificing an exchange. A rook is sacrificed for a knight/bishop with or without a pawn. This can often be seen in closed positions, when the opponent’s rooks have no open files to work on, and the minor pieces feel superior. Tigran Petrosian was famous for his proprietary exchange sacrifices. 

2) A positional sacrifice of a minor piece for one or two pawns. A widespread scenario is sacking a piece for two connected central pawns. For example, you might have seen my game vs Tatiana Kosintseva from the latest Russian Superfinal (included in the short list of best November games at ChessPro).

3) Positional sacrifice of a queen for a rook and bishop (or knight) with/without pawns. For instance, one of the variations in the Dragon is based on sacrificing a queen for a rook and bishop.

When playing a position with a material imbalance, one should be especially careful since even a minor mistake may lead to a quick loss due to lack of material. One needs to approach the game creatively, not the way we look at “normal” positions. To learn how to treat such situations, one has to gain both practical experience and study remarkable games of chess masters. Also, it is important to feel when to go for a material imbalance, and not to be afraid of giving up material.
In the game that I will share with you today my opponent, IM Anastasia Bodnaruk, has positionally sacrificed an exchange.
Pogonina, N. (2472) vs. Bodnaruk, A. (2407)
60th ch-RUS w | Moscow RUS | Round 3| 18 Nov 2010 | ECO: B92 | 1-0
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Be2 Nbd7 7. O-O ( 7. Be3 ) 7... g6 8. Re1 Bg7 9. a4 O-O 10. Be3 e6 11. Nb3 Qc7 12. Qd2 ( 12. a5 b5 ( 12... d5 13. exd5 Nxd5 14. Nxd5 exd5 15. Bd4 ) ( 12... Rd8 13. Qd2 Nc5 14. Bf3 ) ( 12... Nc5?? 13. e5 ) 13. axb6 Nxb6 14. Na5 ) 12... b6 13. Rad1 Ne8 ( 13... Nc5? 14. Qxd6 Qxd6 15. Rxd6 Nfxe4 16. Nxe4 Nxe4 17. Rxb6 Bxb2 18. Bf3 f5 19. Nc5 ) 14. Bh6 ( 14. f4 Nc5 ( 14... Bb7 15. e5 ) 15. Rf1 ) 14... Bb7 15. Bxg7 Kxg7 16. h4 Rd8 17. h5 Nc5?! ( 17... gxh5!? 18. Qg5+ Kh8 19. Qxh5 Nef6 20. Qh4 Rg8 ) 18. Nxc5 Qxc5 ( 18... bxc5 19. h6+ Kg8 20. Qg5 ) 19. Qd4+?! ( 19. h6+ Kg8 20. Qd4 f6 21. Bc4 Nc7 22. Bb3 ) 19... f6 20. hxg6 hxg6 21. Rd3 ( 21. Bc4 Nc7 22. Bb3 ) 21... Rh8 22. Red1 Rh4 23. Qxc5 bxc5 24. g3 Rh7 25. Bf3 Bc6 26. b3 Kf7 27. Ne2? ( 27. Nb1 Ke7 28. Nd2 Nc7? 29. e5 Bxf3 ( 29... d5? 30. Rc3 ) 30. Nxf3 Ne8 31. exf6+ Kxf6 ( 31... Nxf6? 32. Ne5 ) 32. Nd2 Rc7 ( 32... Rhd7 33. Ne4+ Ke7 34. Re1 ) 33. Ne4+ Ke7 34. Ng5 ) 27... Ke7 28. Bg2 e5 29. f4? ( 29. Nc3 Nc7 30. Nb1 Ne6 31. Nd2 ) 29... Nc7 30. R3d2 Ne6 31. a5 Rhh8 32. c3 Rd7 ( 32... Nc7 ) 33. Kf2 c4 ( 33... Rb8 34. Rb1 ( 34. Rb2 c4 35. b4 Nc5 36. Ke3 f5 ) 34... Rb5 35. b4 Rdb7 36. Rbd1 cxb4 37. Rxd6 Rc7 38. cxb4 Rxb4 ) 34. b4 ( 34. bxc4 Nc5 ) 34... Rh2 ( 34... Nc7 35. Ke3 Nb5 ( 35... Rh2 36. Ng1 Nb5 37. Nf3 Rh8 38. Rc2 ) 36. Rh1 ) 35. Kg1 Rxg2+!? 36. Kxg2 Bxe4+ 37. Kf2 d5 38. Ke3 Kd6 ( 38... Nc7 ) 39. fxe5+ fxe5 40. Rf1 Rh7 ( 40... Bd3 41. Rxd3!? cxd3 42. Kxd3 ) 41. Rb2? ( 41. Rdd1 ) 41... Rb7? ( 41... Bd3 42. Rd1 ( 42. b5 d4+ 43. cxd4 exd4+ 44. Nxd4 Bxf1 45. bxa6 ) 42... Ng7 43. Rxd3 Nf5+ 44. Kd2 cxd3 45. Kxd3 Rh2 ) 42. Rd2 Ke7 43. Nc1 ( 43. Rdd1 ) 43... Rb8 ( 43... Kd6 44. Rh2 Bf5 45. Ne2 d4+ 46. cxd4 Rxb4 ) 44. Rh2 Bf5 ( 44... Ng5 ) 45. Rh7+ Kd6 46. Ne2 ( 46. Ra7? d4+ 47. Kd2 Rh8 48. Rxa6+ Kd5 ) 46... d4+ 47. cxd4 Rxb4 48. dxe5+ Kxe5 49. Rc1 Ra4 ( 49... Rb3+ 50. Rc3 Nc5 ) 50. Rc3 ( 50. Rh8 Nc5 51. Re8+ Kd6 52. Rd1+ Kc6 53. Kd4 ) 50... Nc5 ( 50... Kd5 ) 51. Re7+ Kd6 52. Ra7 Ne4 53. Rc1 ( 53. Rxa6+ Ke5 ) ( 53. Rc2 Ra3+ ( 53... Rxa5 54. Rxc4 Ra3+ 55. Kf4 Nf2 ) 54. Kd4 Rd3+ 55. Kxc4 Nd2+ 56. Rxd2 Rxd2 57. Rxa6+ Ke5 58. Nf4 ) 53... Nc5?! ( 53... Ra3+ 54. Kf4 ( 54. Kd4 Rd3+ 55. Kxc4 Nd2+ 56. Kb4 Rb3+ 57. Ka4 Bd3 58. Rc6+ Kd5 59. Nf4+ Kxc6 60. Nxd3 Rxd3 61. Rxa6+ Kc5 62. Rxg6 ) 54... Nc5 55. Rc3 Ra4 ) 54. Rc3 ( 54. Rd1+ ) 54... Bd7 55. Ra8 g5?! ( 55... Ne4 56. Kd4 Bb5 ( 56... Nxc3 57. Rxa6+ Kc7 58. Nxc3 ) 57. Rc2 c3+ 58. Ke3 Rxa5 ) 56. Rg8 g4? ( 56... Ne6 57. Nd4 Rxa5 58. Nxe6 Bxe6 59. Rg6 ) 57. Rg6+ Ke5 58. Rg5+ Kd6 59. Nf4 Rb4? ( 59... Nb3 60. Nd3 ) 60. Rd5+ Kc6 61. Kd4 Nb3+ ( 61... Ne6+ 62. Nxe6 Bxe6 63. Re5 Kd6 64. Rce3 ) 62. Ke5 Bc8 63. Nd3 Ra4 64. Nb2 Rb4 ( 64... Rxa5 65. Rxc4+ Kb7 66. Na4 ) 65. Nxc4 Nc5 66. Rxc5+ Kxc5 67. Nd6+
The game was a roller-coaster. First I let the advantage slip away, then it was Nastya’s turn to act likewise. Black had a comfortable and risk-free position after the sacrifice. White didn’t have any open lines for operation, while Black could keep building up pressure. Nonetheless, my opponent lost her sense of the position, missed a draw a few times, and eventually lost.
P.S. Merry Christmas & a Happy New Year! Kiss
» posted in Middlegame

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