Kenilworth Kibitzer

Taimanov comes up with an original plan to try to crack the Nimzo-Indian, which had served Black very well in this tournament.  To free his bishops White clearly wants to play f3 and e4 (as he virtually always does in the Nimzo-Indian), at which point he would stand better because of the bishop pair and open lines.  Here one crimp to that plan is the knight on c6, which White spends time to eliminate.

11. Ne5   Qc7

12. Nxc6 Qxc6

13. f3    Be6

14. Qe1  Nd7

15. e4

Bronstein: In no other Nimzo-Indian was White able to get in e3-e4 so quickly and effectively, opening diagonals for both his bishops at once.  The slightest misstep from Black could result in his king's falling under a powerful attack - Qh4 is already threatened. 

15. ....  c4?

Bronstein points out 15. .... f5!  as a remedy, a difficult but necessary and indeed good move to make.  In response to White's aggression Black should counter in the center and try to put his transient lead in development to use.  Bronstein supports his analysis with several variations, but more importantly what is the alternative?  The move played seeks to shut down lines and create a defensive wall, but surely Yaacov would cringe at the sight of the forlorn Black bishop - Black is playing a piece down already.

16. Bc2  f5   

17. e5    Rf7

18. a4   a5

19. f4    b5?!

Bronstein: White has a clear plan of attack: h3, Kh2, Rg1, g4, Qg3 or Qh4....Petrosian's attempt to divert his opponent with his extra queenside pawn is understandable, but now a breach appears in his fortress.....

20. axb   Qxb5

21. Ba3   Nb6     (White's 'bad' bishop is sitting pretty)

22. Qh4  Qe8

23. Rf3   Nc8

24. Ba4!  Rd7     (24. ... Bd7  25. e6! Qxe6  26. Qd8+ [Bronstein]; now Petrosian tries his patent exchange sacrifice)

25. Rb1   Qd8    

26. Bxd7!

White is so dominant he can even sacrifice his queen here, getting rook, bishop, pawn and connected passers for his trouble.

26. ....  Qxd7

27. Rg3  Na7

28. Be7  Bf7

29. Qg5  Bg6

30.  h4  Nc6

31. Ba3  Nd8

32.  h5  Ne6

33. Qh4  Bf7

34.  h6  g6

35. Qf6  Qd8

36. Be7  Qc7

and finally the moment we've been waiting for...

37. Rxg6+!  hxg6

38. h7+    Kxh7

39. Qxf7+  Ng7

40. Kf2      1-0

It's probably not so often a defensive master like Petrosian gets punk'd, but there it is.