[Event "Siegen Olympiad"] [Site "?"] [Round "0"] [White "Pomar"] [Black "Petrosian"] [Result "0-1"] [ECO "A40"] [Opening "Queen's Pawn: Modern"] 1. d4 g6 2. c4 Bg7 3. Nc3 d6 4. Nf3 Bg4 5. g3 Qc8 {A very artificial move of the sort that appealed to Petrosian's somewhat unusual taste in back-rank formations.} 6. Bg2 Nh6 {More eccentricity.} 7. h3 Bd7 8. e4 f6 {Petrosian comm ents: "After 8 moves Black has a bad position. White has obtained the ideal pawn center, has developed his pieces and can initiate an attack without difficulty."} 9. Be3 Nf7 10. Qd2 c5 11. dxc5 { It would have been better to advance this pawn and keep the position closed.} 11... dxc5 12. O-O-O Nc6 13. Kb1 {13.Bxc5 Na5 14.b3 Qxc5 15.Qxd7+ Kf8 Black will be able to mount a strong counterattack on the queenside.} 13... b6 14. g4 {Pomar knows he has a good game, but has no idea what to do with it. This is an aggressive move with no particular point.} 14... Rb8 15. Rhe1 Rb7 16. e5 fxe5 {Here Black might have engaged in a promising exchange sacrifice: 16... Nfxe5 17.Nxe5 Nxe5 18.Bxb7 Qxb7} 17. Ng5 O-O {Now each side has an outpost on the d-file. White should have occupied it with the bishop.} 18. Nd5 Nxg5 19. Bxg5 Be8 20. Bh6 e6 21. Bxg7 Rxg7 {Black has easily repulsed the mini-attack.} 22. Nc3 Nd4 {Now Black seizes the initiative. Notice that the d5-square is no longer available for use by the White pieces.} 23. Rxe5 Rgf7 24. Ne4 Qc7 { The rook is going to get trapped.} 25. Rg5 Rf4 26. Qd3 h6 27. Nd6 hxg5 28. Nxe8 Rxe8 29. Qxg6+ Kf8 30. Qxg5 Qh7+ { and Black resigned because smothered mate is coming)} 31. Ka1 Nc2+ 32. Kb1 Na3+ 33. Ka1 Qb1+ 34. Rxb1 Nc2# 0-1