[Event "Copenhagen"] [Site "?"] [Round "0"] [White "Petrosian"] [Black "Larsen"] [Result "1-0"] [ECO "A53"] [Opening "Old Indian: 3.Nf3 Bg4 4.Nc3"] 1. d4 Nf6 2. c4 d6 3. Nf3 Bg4 {An unusual opening, but playable.} 4. Nc3 Nbd7 5. e4 e5 6. Be2 Be7 7. O-O O-O 8. Be3 Bh5 {Since White will exchange bishops anyway (by Nd2), this amounts to a waste of time. Better was 8...c6.} 9. Nd2 Bxe2 10. Qxe2 exd4 {Black exchanges in the center. Otherwise White would play pawn d5 giving Black a bad bishop.} 11. Bxd4 Re8 12. f4 Bf8 13. Rad1 a6 { White has a big space advantage which means a greater choice of plans.} 14. Qf3 c6 15. g4 {With the Black pieces so cramped they don't have room to defend against the direct kingside attack.} 15... Nc5 16. Bxc5 dxc5 {White has g iven Black doubled c-pawns. While gaining a 4 to 3 majority on the kingside. In effect Black is a pawn down.} 17. e5 Nd7 18. Nde4 Qc7 19. Rd3 { From d3 the White rook keeps an eye on both the d-file and h3 square.} 19... Nb6 20. b3 Rad8 21. Rfd1 Be7 22. g5 { The pawn makes way for the decisive kingside attack.} 22... Nc8 23. Qh5 Rxd3 { 23...g6 24.Qh6 Rxd3 25.Rxd3 Rd8 26.Nf6+ Bxf6 27.exf6 Rxd3 28.Qg7++} 24. Rxd3 { White's kingside pawn majority is amplified by the fact that one of the pawns occupies a strong position at e5.} 24... Rd8 { Here White has a crushing sacrifice. Can you find it?} 25. Nf6+ { A sacrifice which opens up the Black king.} 25... gxf6 26. Rh3 Kf8 27. Qxh7 Ke8 28. g6 Bf8 {28...fxg6 29.e6 takes away Black's flight square.} 29. g7 Bxg7 30. Qxg7 {Although, material is equal White still has a winning attack.} 30... Qe7 {30...Kd7 31.Rd3+ Ke8 32.Qh8+ Ke7 33.exf6+ Ke6 34.Qxd8} 31. Ne4 Rd1+ 32. Kf2 f5 33. Nf6+ Kd8 34. Rh8+ { Black resigned as his queen will be trapped next move. 34.Rh8+ Kc7 35.Re8} 1-0