[Event "Soviet Championship"] [Site "?"] [Round "0"] [White "Polugaevsky"] [Black "Petrosian"] [Result "0-1"] [ECO "E47"] [Opening "Nimzo-Indian: 4.e3 O-O 5.Bd3"] 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 O-O 5. Bd3 d5 6. Nf3 c5 7. O-O dxc4 8. Bxc4 Nbd7 9. Qe2 a6 10. a3 cxd4 {Black could also keep the tension with 10...Ba5.} 11. axb4 dxc3 12. bxc3 {At a first glance the position seems to favor White with the two bishops. However, Black will have play against White's backward c-pawn.} 12... Qc7 13. Bb2 e5 { Gains space and makes an out for the light squared bishop.} 14. e4 Nb6 15. Bd3 Bg4 16. Ra5 Nh5 17. g3 {Played to prevent Nf4.} 17... Rad8 18. Qe3 f6 19. Rc5 Qd7 20. Be2 {A mistake which was extremely hard to foresee. The bishop will come under attack on e2. Better was 20. Bc2.} 20... Bh3 21. Ra1 Nf4 { White gets mated if he takes the knight.} 22. Rca5 { 22.gxf4 Qg4+ 23.Kh1 Qg2+ Mate.} 22... Qg4 23. Bc1 Rd6 24. R5a2 Rfd8 { The domination of the only open file is the key to victory in this game.} 25. Ne1 {White must protect the vulnerable back rank.} 25... Nxe2+ 26. Qxe2 Qxe2 27. Rxe2 {White has defended well to get this far. However, Black's initiative carries into the endgame.} 27... Rd1 28. f3 Nc4 { 28...R8d3 This would have been more efficient.} 29. Kf2 { White finally gets off the back rank.} 29... R8d3 30. Rc2 Rd7 31. g4 { A vain attempt to snare the bishop.} 31... g5 32. Rca2 { 32.Kg3 Rxe1 33.Kxh3 Rdd1} 32... h5 { Opening yet another avenue into White's kingside.} 33. gxh5 Be6 34. Re2 Rh7 35. Ng2 Rxh5 {Now White's pawn structure is too weak.} 36. h4 { White gives up a pawn to keep the rook out of the attack.} 36... gxh4 37. Re1 Rxe1 38. Nxe1 Rh7 39. Nc2 h3 40. Be3 Rd7 41. Re1 Kh7 42. Ke2 Nb2 { Being a clear pawn up Black decides the game quickly.} 43. f4 Nd1 44. f5 Bc4+ 45. Kf3 Rd3 46. Rh1 Bb3 47. Rxh3+ Kg8 { White resigned due to the pin on his bishop.} 0-1