Sicilian Defense Paulsen (Kan) Variation

JOHN NUNN vs. ANDREI SOKOLOV
Dubai, 1986

1. e4, c5
2. Nf3, e6
3. d4, cxd4
4. Nxd4, Nc6
5. Nc3, a6

The Paulsen (Kan) Variation, named after Ilya Kan. By playing 5...a6, Black prevents Nb5 and prepares an eventual ...b5 advance.

6. Be2, d6
7. Be3, Qc7
8. f4, Na5
9. 0-0, Nc4

Black is harassing the strategically located e3 Bishop. 

10. Bxc4, Qxc4
11. f5, Be7
12. Qg4, h5
13. Qf3 ....

Not 13. Qxg7 because Black replies with Bf6 attacking both the Queen and the Knight at d4.

13. .... Bf6
14. gxe6!!, fxe6

Not 14....Bxd4 because White's attack 15. Qxf7+ Kd8, 16. e7+ would be fatal for Black.

15. e5!, dxe5

Not 15....Bxe5 because of 16. Qf8+ Kd7, 17. Rd7+ with a mating threat.

16. Ne4!! ....

Threatens Nd6 double-check....

16. .... Qc7
17. Qg3!! ....

Prevents the capture of the Knight at d4.  It is delightful to see how Nunn managed to pin pieces one after another.

17. .... Ne7

Preventing 18. Qg6+, but still insufficient to hinder White's attack.

18. Rad1, h4
19. Nxf6+, gxf6
20. Qg7, Rf8
21. Rxf6, Rxf6
22. Qxf6, Qd6

After 22....exd4, 23. Rxd4, White controls much of the central squares and threatens mate at f8 after 24. Bh6.

23. Bg5, exd4
24. Rxd4!! ....

The Rook cannot be taken because of the mating threat at e7.

24. .... Nd5
25. Rxd5, Resigns

White's Rook is invincible. If 25...exd5, then Black loses his Queen.

Magnificent play by John Nunn!

Queen's Indian Defense, Classical Variation - Polugayevsky Gambit

GARRY KASPAROV vs. SLAVOLJUB MARJANOVIC
Malta 1980

1. d4, Nf6
2. c4, e6
3. Nf3, b6
4. g3, Bb7
5. Bg2, Be7
6. 0-0, 0-0
7. d5!, exd5
8. Nh4 ....

The Polugayevsky Gambit.  White sacrifices a pawn to secure the f5 location for the King's Knight.

8. .... c6
9. cxd5, Nxd5
10. Nf5!, Nc7
11. Nc3, d5
12. e4! ....

This sharp move intends to weaken Black's central pawn structure.

12. .... Bf6
13. exd5, cxd5
14. Bf4, Nba6
15. Re1 ....

Taking control of the e-file.

15. .... Qd7
16. Bh3, Kh8

Black avoids the disastrous Nh6+.

17. Ne4!!, Bxb2
18. Ng5, Qc6?

Black intends to threaten mate at h1, but only manages to displace the Queen.

19. Ne7, Qf6
20. Nxh7 ....

The Knight cannot be taken because 21. Qh5+ threatens mate.

20. .... Qd4
21. Qh5, g6
22. Qh4, Bxa1
23. Nf6 dis chk, Resigns

After 23....Kg7, there are several ways of mating Black.  One line is 24. Qh6+ Kxf6, 25. Bg5 mate.

Another line is 24. Bh6+ Kh8 (or Kh7), 25. Bxf8 mate.

Benoni Defenxe, Taimanov Variation

GARRY KASPAROV vs. JOHN NUNN
Luzern olm, 1982

1. d4, Nf6
2. c4, e6
3. Nc3, c5
4. d5, exd5
5. cxd5, d6
6. e4, g6
7. f4, Bg7
8. Bb5+, N6d7

The most common reply is 8....Bd7.  Clearly the chosen move is an invitation to complication.

9. a4, Na6
10. Nf3, Nb4
11. 0-0, a6
12. Bxd7, Bxd7
13. f5!, 0-0
14. Bg5, f6
15. Bf4, gxf5?

Desperately grabbing a pawn, but Black only gets into a worse position.

16. Bxd6, Bxa4
17. Rxa4, Qxd6
18. Nh4!! ....

Preparing the Knight for a more powerful location....

18. .... fxe4
19. Nf5!, Qd7
20. Nxe4, Kh8
21. Nxc5, Resigns

White gains material after 21....Qxd5, 22. Qxd5 Nxd5, 23. Ne6, and at least a pawn to Rd4.

If 21....Qb5, then 22. Ne6 Rf7, 23. N5xg7 Rxg7, 24. Nxg7 Kxh7, 25. Qg4+ Kh8, 26. Rxb4 and White is a piece ahead.