1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. Bd3 Nf6 6. O-O d6 7. c4 b6 8. Nc3 White has two main attacking plans, which are distuinguished by the development of his queen's bishop. Firstly he may build up a slow kingside attac by b3, Bb2, Nc3, Qe2, f4, Rae1 and so on, with the aim of a breakthrough by f5. The other plan is to prepare e5 by Nc3, Qe2, f4, Bd2 and Rae1. The important point is that with the bishop on b2 the e5 plan is much less effective, because White ends up with a pawn on e5 and this would block the bishop on b2.
8... Bb7 9. f4 Be7 10. Kh1 O-O 11. Qe2 Moves such as Qe2, Kh1 and f4 are logical because they do not commit White to one plan or the other. My view is that the e5 plan is most effective against ...Nbd7 by Black, because then the queen's knight blocks the retreat of the one on f6. Therefore it is often useful to delay committing the c1-bishop until Black has moved the b8-knight. Against ...Nc6 White will take on c6, then play b3 and Bb2, and against ...Nbd7 White will continue with Bd2 and Rae1.
11... Nc6 12. Nxc6 Bxc6 13. b3 Nd7 13... Qc7 14. Bb2 Rad8 15. Rae1 Bb7 16. Bb1 Nd7 17. Qh5 Rfe8 18. Re3 Nf6 19. Qh3 g6 20. f5 Bc8 21. Rg3 Kg7 22. Qh4 Rf8 23. Bc1 Rde8 24. e5 dxe5 25. Qh6+ Kh8 26. Rh3 Rg8 27. Bg5 Rg7 28. Bxf6 Bxf6 29. Ne4 Qd8 30. fxg6 Be7 31. Qxh7+ Rxh7 32. Rxh7+ Kg8 33. gxf7+ Kxh7 34. fxe8=Q 1-0, Nunn-Gheorghiu, Biel 1983
14. Bb2 g6 15. Rad1 The purpose of this (rather than Rae1) is to prevent the development of Black's e7-bishop to the long diagonal. After 15...Bf6, for example, 16.Bb1 Qc7 17.Qd2 attacks d6.
15... Re8 16. Bb1 Qc7 17. Qd3 A flexible move attacking d6 and preparing Qd4 or Qh3 according to circumstance.
17... Bf8 18. Nb5!? As shock for Black.
18... Bxb5 The point is that after 18... axb5 19. Qc3 e5 20. cxb5 Rac8 21. bxc6 Qxc6 22. Qf3 Black cannot exchange on f4 since he has no satisfactory way to cover f7, so White gets to play 23.f5, when Black's light squares look very sicky.
19. cxb5 axb5 19... a5 20. Rc1 Nc5 21. Qc3 is much worse as Black has to play the weakening 21... e5
20. Qxb5 Qb7 The upshot of White's mini-combination is that he has the two bishops and a queenside pawn majority.
21. Qe2?! Now 21. a4! would have been logical, relieving the b1-bishop of its defensive duty and pinning down the b6-pawn. If Black remains passive the b1-bishop can e eventually move to b5. During the game I was concerned about the reply 21... Nc5 22. Qc4 Rac8 but 23. f5 e5 24. Rf3 gives Black no way to exploit the position of White's queen (24... Ne6 25.fxe6!) and consolidation by 25.Qe2 will be good for White.
21... b5! 22. b4 Ra6 23. Rf3! Bg7 24. Bxg7 Kxg7 25. Rfd3 Qc7 26. Rh3 Rb6 27. Qd2 Nf6 28. f5 exf5 29. exf5 d5! 30. fxg6?! 30. Rf1!
30... fxg6 31. Rf1 Ng4! 32. Qd4+ Rf6 33. Bd3 h5 34. Rxf6 Nxf6 35. Rf3 Re1+ 36. Bf1 Qe7?! 36... Qd6!
37. Kg1 Re4 38. Qc3 d4 39. Qd3 Ng4? 40. h3
1-0
