IM Tibor Karolyi - Luke Leong Simultaneous Chess Exhibition, 2 Mar 02 E20 Nimzo Indian Defence 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. f3 c5 5. d5 d6 6. e4 e5!? Black seeks to transpose into some 4. Bg5 variations of the Nimzo Indian Defence. While the move 6. … e5 has not been previously seen in any GM games, Black does not appear to face any problems with it. ECO cites 6. … 0-0 7. Bd2 Re8 8. Nge2 exd5 9. cxd5 Nbd7 10. Ng3 a6 11. Be2 b5 12. 0-0 Ne5 13. a4 bxa4 14. Nxa4 Bxd2 15. Qxd2 Rb8 = (Dreev - Salov, Biel Interzonal 1993). However, 6. … Bxc3+!? (first wrecking the White pawn structure) 7. bxc3 e5!? (J. Petronic) may be even better than the text. 7. Nge2 Qe7 8. g4 Na6 The idea is to manoeuvre this knight to c7 to support queenside expansion with the pawn thrusts a6 and b5. I felt 8. 0-0 was premature as White's kingside pawn structure is not yet fixed. 8. Nfd7 (Fritz 5.32) is a reasonable alternative. 9. a3 Bxc3+ 10. Nxc3 Nd7 This knight is heading for g6 via f8, where it will exert its influence over the f4 and h4 squares (should White push 11. h4 and Black reply 11. h5 with 12. g5 Ng6 to follow). Black simultaneously threatens 11. Qh4+, harassing the White king. 11. Be3 This gives Black the option of effectively isolating White's g pawn, as will be seen in a few more moves. 11. h4 leads to the line mentioned above. 11. … h5 12. g5 h4 13. Rg1?! An unnecessary move, since the g5 pawn is adequately defended and the threat of g6 can be easily parried. Either 13. Nb5!? paralyzing Black's a6 knight or 13. Bh3!? intending to trade the problem light squared bishop for one of Black's superior minor pieces (in a closed position) would offer White better prospects for an advantage. 13. … Nf8 14. b4 b6 Definitely not 14. … cxb4? 15. axb4 Nxb4?? 16. Qa4+! picking up a piece for a pawn. 15. Bd3?! The bishop isn't doing much here. Fritz 5.32 gives 15. Qa4+! with a slight advantage to White owing to the discoordinated Black forces. After 15. … Kd8 (15. … Qd7? 16. Nb5! ê 17. f4!) Black will require some time to unravel his position. 15. … Ng6 16. Ne2 The queen check is not so effective now, with the f4 square under Black's control and Black's king free to castle - 16. Qa4+?! Qd7 17. Nb5 0-0 and 18. f4 undermining Black's e5-d6-c5 pawn chain is not possible. 16. … Bd7 17. Rb1 Protecting the b4 pawn, now that the tactical defence Qa4+ is not possible. 17. … 0-0 = Black has completed his development and is now ready to attack White's f3-e4-d5-c4 pawn chain with the levers f5 and b5. 18. Kd2 Rab8 I wanted to create some play on the queenside while retaining the option of the freeing pawn advance f5, hence not 18. … Rfc8 first. With 18. … Rab8 Black threatens to play b5 in the near future, possibly after the strengthening move Rfc8. 19. b5 Nc7 20. a4? Unnecessarily placing another pawn on a light square, White probably underestimated the strength of Black's response. 20. f4!? was called for, after which Black maintains the balance with 20. … exf4 21. Nxf4 Ne5 22. Be2 Ng6! = (Fritz 5.32). 20. … f5! Capturing this pawn with either the e4 or g5 pawns allows Black to play against the backward f3 pawn - 21. exf5 Bxf5 22. Qc2 Bxd3 23. Qxd3 Qf7 or 21. gxf6 ep Qxf6 ê 22. … Kh7, but White's reply leaves him without any counterplay. 21. Qc2? f4! It becomes clear that White's "isolated" g5 pawn, which can at most be defended once, will eventually fall. 22. Bf2 a5! =+ Snuffing out any ideas of queenside counterplay based on 23. a5 and fixing the pawn weakness on a4. (This will prove to be useful later on.) Black now has a noticeable advantage as White's bishop pair is badly hampered by the blocked pawn configuration. 23. Nc3 Kf7 If 23. bxa6 ep?! then 23. … Nxa6 ê 24. … Nb4, 25. … Ra8 with pressure on White's a4 pawn. 23. ... Kf7 Black prepares to use the h file for major piece operations. 24. Rh1 h3!! A subtle move which prevents White from constructing a defensive setup beginning with the pawn move h3 - 24. … Qxg5?! 25. Rbg1 ê 26. h3! and Black faces some difficulties in breaching White's position. Moreover, there is no hurry to capture White's indefensible g5 pawn. 25. Rbg1 Rh8 26. Qd1 Rh5 27. Qf1 Rbh8 28. Nd1 Ne8 29. Be1 Rxg5 30. Rxg5 Qxg5 31. Rg1 Qd8!? Planning to challenge the g file by means of Nf6, Rh5, Qh8, Qh6 and Rg5. Fritz 5.32 recommends 31. … Qh5!?, although I feel this interferes with the movement of the h8 rook. 32. Nf2 Nf6 33. Be2 Rh5 34. Kd3 Qh8 35. Ng4 Nh4! Capturing on g4 allows White to stop all of Black's breakthroughs with 36. fxg4 and 37. Bf3!. 35. … Nh4! eyes the g2 square as a potential outpost and thus practically forces White's reply, which hands Black a winning endgame advantage. 35. … Rg5 is also playable. 36. Bxh4 Rxh4 37. Nxf6 Kxf6 38. Qd1 Rh6 39. Qf1 Qe8 Directly 39. … Rg6 is probably sufficient to win but I wanted to improve the position of my queen first. 40. Qd1 Qh5 41. Qe1 Qh4 42. Qf1 After 42. Qxh4+ Rxh4 Black also wins by advancing his g pawn (similar to what happened in the game). 42. … Rg6 43. Rxg6+ Kxg6 44. Qg1+ Qg5?? Under the mistaken impression that the resulting position is easily won, I offered to trade queens, which turns out to be White's sole defensive resource (!). 45. … Qxg5+ White seizes his drawing chance. If 45. Qf2 Black penetrates White's position decisively - 45. … Qg2! 46. Qh4 Qxh2 47. Qe7 Qg1! 48. Qxd7 Qe3+ 49. Kc2 Qxe2+ 50. Kc1 Qxf3 -+ (Fritz 5.32). 45. … Kxg5 46. Kd2 Kh4 47. Ke1 g5 48. Kf2 g4 49. fxg4?? By leaving his pawn structure intact and waiting with his bishop White can draw(!) (Karolyi). 49. Bd1!! gxf3 50. Bc2!! ê Bd3, Bc2 or 49. … g3+ 50. Kg1!! ê Bd1, Be2 and Black cannot breach White's setup (!). 49. … Bxg4 50. Bf3 If White's bishop leaves the d1-h5 diagonal 50. … Bd1 ê Bxa4 wins easily. 50. … Bxf3 51. Kxf3 Kg5 52. Ke2 Kg4 53. Kf2 f3 54. Ke3 f2! 0-1 55. Kxf2 Kf4 -+