Opposite Coloured Bishops

Transcription

1 Opposite Coloured Bishops Matt Marsh GAME 1: M. M. Marsh D. Chancey Kings Island Open, Nov. 11, Rc1 Bb6 4. Bb3 Re8 5. Rhe1 f5 6. Rcd1 Kh Rfd8 This position is about even because of opposite coloured bishops. Opposite coloured bishops are when the bishops are on different color complexes. Positions that arise from opposite coloured bishops tend to look drawish. However, don't just take a draw just because there's opposite coloured bishops on the board. If it looks favorable for yourself try to win it! That doesn't mean you will always succeed of course. 2. Kb1 Prophylactically white sees the threat of Bd4 now Rd6 This is an odd spot to set the king. e4 would be perfectly fine and if he wants to move the king it would be to g7.(if e4 24. Bc2 e3 25. Bxf5 Re5 26. Bc8 Rexd5 27. Rxd5 Rxd5 28. Re2 Rd2 29. Rxd2 exd2 30. Kc2 Bd4 31. Bxb7 Bxb2 32. Kxd2 and the position should be drawn). 7. Bc2 White takes his opportunity and solidifies the center and kingside f4 8. g4 Black has the worse position because of his doubled pawns. White also has a passed pawn in the position. But this might still not be enough to win. So black, with the move Rd6, is just trying to set up an unpenetrable fortress. White is playing for the win and must carefully set his pieces in the right position. If white doesn't play g4 it could become a potential target for black in the future.

2 8... f6 9. Bf5 Red8 10. Be6 Kg7 11. Rc1 Rh8 12. Re2 Rdd8 13. Rec2 h5 14. Rg Kh6 21. Kb3 Ra8 22. Rc8 White could have a better chance after gxh5 or Rd h4 15. h3 Rhe8 16. Rc4 White misjudges the ending. (if 39. Bc8 Ra7 40. bxa5 Bxa5 41. d6 Rd8 42. d7 Ra6 43. Rc5 Rb Ka2 Bb4 45. Rd5 Be7 46. a5 Rb4 47. Rb2 Ra Kb1 Ra3 49. Bxb7 Rxf3 50. a6 Ra3 51. Ra2 Rxh3 52. a7 Rb Kc2 Rxb7 54. a8=q) Raxc8 23. Rxc8 Rxc8 24. Bxc8 e4 25. fxe4 f3 26. Bxb7 Kg5 27. bxa5 Bxa5 28. Ba6 33. g5 Re7 34. Rg4 Bf2 35. Rc2 Bg3 36. b4 Kg6 37. gxf6+ Kxf6 38. Kb2 is interesting Kg6 17. a4 Rd6 18. Rgc2 Rdd8 19. b4 a5 20. Ka2 45. d6 Kf4 46. Kc2 f2 47. Ba6 Kxe4 48. d7 Kf4 49. Bf1 Kg3 50. Kd3 Kh Kf4 29. Bf1 Kxe4 30. Kc4 Ke5 31. Kb5 Bd8 32. Kc6 if 37. bxa5 Bxa5 38. Rc5 Ra8 39. Bf5+ Kg5 (39... Kf7 40. Rb2 Reb8 41. d6 Kf8 42. d7 Bd8 43. Rc8) 40. d6 Red8 41. d7 Ra6 42. Rb2 49. a5 Bxa5 50. Kxa5 Kxd5 51. Kb6 Ke4 52. Kc6 Kf4 53. Kd7 f5 54. gxf5 Kxf5 55. Ke7 Kg6

3 32... f2 33. d6 Ba5 34. Bg2 8. bxc3 Nd5 if 51. Ba6 Kf4 52. Kb7 Ke5 53. d7 Ke6 54. Kc8 Ke7 and white can't make progress Bd8 35. Kc5 Ba5 36. Kb5 Bd8 37. Kc6 Ba5 38. d7 Ke6 39. Bd5+ Ke7 40. Bc4 Bd8 Probably Nd5 is the reason Joseph played Bxc3. However, he misses a prolific move. 9. e4 1/2-1/2 GAME 2: M. Marsh J. Moon Boris Kogan Memorial, Oct. 7, d4 d5 2. c4 e6 3. Nf3 Nf6 4. g3 c6 5. Bg2 dxc4 6. Ne5 Bb4+ 7. Nc3 Bxc3+ Sending the knight back to f Nf6 (If 9... Nxc3? 10. Qf3, which picks up the c3 knight because of the threat Qxf7.) 10. Nxc4 White has a definitive advantage because of the bishop pair and because he has more space. Giving the bishop pair immediately. Usually in the Nimzo-Indian this is fine but in this particular position it gives white an advantage.

4 10... b5 11. Ne3 O-O 12. Ba3 Re8 13. e5 Nd5 14. Qb3 a6 18. Rxe3 Qb6 White is not worried about doubled pawns after Nxe3. After castling, he will get an open file for his rook and the pawn on e3 will advance and help support a large pawn advance in the center. Black has further downgraded his position by making his one bishop bad. 15. O-O Nd7 16. Rfe1 Black makes an excellent move threatening c5. The tactics after c5 Bxb7 and c4! work out for black also so white must make a strong reply. 19. c4! Now was probably the chance to make an invincible bishop on d6. (After 16. Bd6 N7b6 17. Rac1 its hard for black to find any counterplay.) Bb7 17. f4 Nxe3 The pawn on d4 can't be touched because of Rd1 and now c5 doesn't work because after Bxb7 there is no c4 anymore. Now white is threatening c5 himself which black can't stop a5 (if c5 20. Bxb7! and white has juicy options, e.g. 20. dxc5!, 20. Bxc5!) 20. c5 Qc7 21. g4 Nf8 Black times his capture correctly after white moves his f-pawn. Making the best use of his knight. It's going on a long tour of Ng6-e7-d5 where it is well posted.

5 22. Bb cxd5 27. fxe6 fxe5 28. Qxb5 Ba6 As things have turned out, white has unfortunately given himself a bad bishop. But you can't have everything, so he makes the best use of it by defending the weak pawn on d Ng6 23. Rf1 Ne7 24. f5 Nd5 25. Rh3 f6 Better is Rxe6 29. Qd3 e4 30. Qe3 Rg6 31. g5 with a slight advantage to white. 29. Rf7 Maybe rushing things to open the position. 26. Bxd5 One simple way of getting out of the skewer by the bishop (29. Qd7! Qxd7 30. exd7 Re7 31. c6! Bxf1 32. Kxf1 exd4 33. Rh5 +/-) Re7 30. Rxe7 Qxe7 31. Qd7 White misses his opportune time to strike on e6. (26. fxe6! Rxe6 27. Qd3 h6 28. Bxd5 cxd5 29. exf6 Rf8 30. fxg7 Rxf Qxf1 Qe7 +/-) (31. Qc6! Bb7 32. Qd6 Qg5 33. Rg3 +/=).

6 31... Qf6 32. Qf gxh5 Bxh5 40. c6 Be8 41. c7 Rc8 42. Rc3 Bb5 43. Rc5 Bc4 44. a3 Kd7 45. Kf4 Forced. Black was looking for Qf Qxf7 33. exf7+ Kxf7 34. dxe5 Bc4 White must realize before he moved his c-pawn that he would be giving up. But in return, he gets rooks off (a key thing in this position) and will invade with his king. Fortunately, he has another passed pawn Rxc7 46. Rxc7+ Kxc7 47. Kf5 Bd Ke6 Kc6 49. Ke7 g5 So here we are in a position where most people would just shake on a draw. After the topsyturvy middlegame, all white obtains is an extra pawn in an opposite coloured bishop endgame. However, if you look at the position a second time you might notice white has two passed pawns. So the main point is, JUST BECAUSE IT IS AN OPPOSITE COLOURED BISHOP ENDGAME DOES NOT MEAN IT IS A DRAW. So white played on to win. 35. Ra3 (35. Rxh7 Bxa2 36. e6+ is interesting.) a4 36. Bd4 Ke6 37. Kg2 Be2 38. Kg3 h5 Black realizes his dilemma and tries to run for it with his king and pawns. 50. e6 Bb5 51. Kf7 g4 52. e7 Kd6 53. e8=q Bxe Kxe8 Ke6 In the long run, this makes things worse for black. Later it will give white an invasion point for his king. As mentioned before, black starts to make his run.

7 55. Bb2 Kf5 56. Kd7 Ke4 57. Kc6 d4 58. Kb5 d3 59. Bc3 Ke3 60. Kxa4 d2 61. Bxd2+ Kxd2 62. Kb5 And white wins. After the pawn race white will have a queen verse a knight pawn which is a winning position. 1-0