[Event "Petersburg"] [Site "?"] [Round "0"] [White "Lasker"] [Black "Tarrasch"] [Result "1-0"] [ECO "D02"] [Opening "Queen's Pawn: Krause, 3.c4"] {Bishop and Rooks cooperate to win the open file} 1. d4 d5 2. Nf3 c5 3. c4 e6 4. cxd5 exd5 5. g3 Nc6 6. Bg2 Nf6 7. O-O Be7 8. dxc5 Bxc5 9. Nbd2 d4 10. Nb3 Bb6 11. Qd3 Be6 12. Rd1 Bxb3 13. Qxb3 Qe7 14. Bd2 O-O {The position has various well marked features, such as the isolated d-pawn, and the White light-square Bishop in fianchetto; the open c-file is not quite such an overriding characteristic this time. Nevertheless, as the sequel shows, it still has an important part to play} 15. a4 $3 {The intention is to march this pawn to the sixth rank where it will undermine the position of the Black Knight. The result will be that Black will be unable to other sufficient resistance in the c-file} 15... Ne4 (15... Qxe2 16. Re1 Qa6 17. Bf1 { Trapped piece}) (15... Bc5 16. a5 a6) 16. Be1 Rad8 {It seems from this move that Black was not aware of the danger threatening on the c-file. Otherwise he would have played this Rook to c8} 17. a5 Bc5 18. a6 bxa6 (18... b6 19. Qa4 { White breaks all resistance in the c-file ... followed by Pb4}) 19. Rac1 $1 { This is the whole point of the preceding maneuvers. Notice also that the advance of the a-pawn has made the White light squared Bishop very active, for the removal of the Black b-pawn has weakened the whole of the long white diagonal} 19... Rc8 20. Nh4 $1 Bb6 (20... -- 21. Bxe4 Qxe4 22. Rxc5) 21. Nf5 Qe5 22. Bxe4 Qxe4 23. Nd6 {Tactic based on fork} 23... Qxe2 24. Nxc8 Rxc8 25. Qd5 {Thus White forces a speedy exchange of Rooks, and so reduces his task to one of technique.} 25... Qe6 26. Qf3 h6 27. Bd2 Ne5 28. Rxc8+ Qxc8 29. Qe4 Nd7 30. Rc1 Qf8 31. Bxh6 {fork tactic} 31... Nc5 32. Qg4 f5 33. Qg6 Qf7 34. Qxf7+ Kxf7 35. Bg5 Nd3 36. Rb1 $1 Ke6 37. b3 Kd5 38. f3 a5 39. h4 Nc5 40. h5 d3 41. Kf1 a4 42. bxa4 Nxa4 43. Bf6 $1 Ke6 44. Bxg7 Kf7 45. Be5 Nc5 46. Rd1 1-0