keypusher: Anand could only dream of a Petroff like this one in Mexico.After 14....Ncxe4?! (14....Ngxe4 is more natural) 15. dxe5 Bc5 16. Bg3 Nh6 17. Qc2 forces a kingside weakness. Still, Fritz isn't terribly concerned, and probably rightly so. 19th-century masters worried about moves like ...g6 much more than modern masters do.
Fritz likes simplification with 20....Nxd4 21. cxd4 Nxd4 22. Bxg6 hxg6 23. Qxd4 Qb6 24. Qd2, although Black's dark-square weaknesses around the king would frighten any human. After 20....Qd7 21. Bg5 this simplification is no longer possible: 21....Nxd4 22. cxd4 Bxd4 23. Bxg6 hxg6? (23....fxg6 is less bad) 24. Bf6! Kh7 25. Qxd4 Bg4 26. f3 wins.
25....Nxe6 leaves Black's pieces in less of a snarl than 25....Qxe6, although White remains better after 26. Bf6.
After the panicky 26....h5?! 27. Rg1 hxg4? 28. Rxg4 it's all over, e.g. 28...d4 29. Rh3 Nh5 30. Bf6 Bg7 31. Qxh5!! Qc6+ 32. f3 gxh5 33. Rxg7+ Kf8 34. Rgh3. Black has nothing better than 34....Qxf6 35. exf6 Re1+ 36. Kg2, after which Fritz spies a mate in nine.
In the actual game, 31. Qh8 is mate, of course.
Soltis wrote that Tarrasch's best games were <linear -- an opening advantage grew logically and steadily until, by move 30 or 35, it became overwhelming.> Here is a classic example of that kind of game.
Kibitzing
sac: 30.Rh3
