1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4 The Nimzo-Indian is an essential part of almost every top player's repertoire. 4. g1f3  4... e8g8  5. a2a3  5... b4c3  6. b2c3  6... c7c5  7. g2g3  7... b7b6  8. f1g2  8... c8b7  9. d4d5 Tabatabaei occupies as much space as he can before his pawns stall. 9... d7d6 So is placing his pawns on the opposite color of the bishop he is left with, a classical strategy in the Nimzo-Indian. 10. e1g1  10... d8e7  11. f3h4  11... b8d7 All these logical developing moves have been seen before and Black now starts to threaten concretely the more exposed of the doubled c-pawns. 12. f1e1 Tabatabaei decided not to defend it, with a novelty $1 12... d7e5 So principally accepts the pawn. 13. e2e4  13... e5c4  14. g2f1  14... c4e5  15. c3c4 The center has been Solidified and Tabatabaei is ready for the f2-f4 advance. 15... e5g6 Black is correctly fighting the opponent’s active pieces. 16. h4g2 More pieces mean more chances and Tabatabaei is in a must-win situation. 16... b6b5 The center needs to be destroyed $1 17. c4b5  17... e6d5  18. e4d5  18... e7d7  19. g2e3  19... f8e8 A curious moment. So wants to regain the pawn in the most comfortable way. 20. c1b2 White insists on the pawn sacrifice $1 20... f6d5  21. e3d5  21... e8e1  22. d1e1  22... b7d5 Not only did So win the pawn back, but he also opened a strong diagonal for his bishop. Still, Tabatabaei has plenty for the material and brings his last piece into the game with 23. a1d1 And just when So seemed to control the situation he blunders with 23... g6h4  24. d1d3 An only move, but one that not only defends but wins $1 24... d7g4  25. e1c3  25... d5e4  26. f1e2  26... g4g5  27. d3d6  27... h4f5  28. c3e5  28... g5e7  29. e5e7 