THE TENSION in the Emperor's Ballroom in Caesars Palace, Las Vegas, has risen to almost unbearable levels in the last few days as play moves inexorably towards the quarter-finals of the Fide world championship.

I logged on to the Internet Chess Club (http://www.chess after about half an hour's play of the first round of the last 16 on Monday - just after 11.30pm London time - for a "quick look", but so riveting was the action that I remained glued to it for the next three-and-a-half hours.

In the end, apart from Nigel Short's debacle below, all the other seven games, including Adams vs Dreev, were drawn: I fear Short went out after a draw on Tuesday and further bloodshed propelled Akopian through to join Shirov. But the other six matches ended one-all, leaving ample scope for utter mayhem in the play-offs last night.

9 Bb5+ is the normal theoretical move, though not very well explored. 13 ...e5 led to quite incalculable mayhem after 14 Qh5. Not then 14 ...exd4?? 15 Nxf6! Bxf6 16 Bd3 forcing mate, but after 14 ...Nd5! probably Shirov should have played 15 Ne2 which is about equal. 17 Bxc4 fxe4 18 Bxd5 Qb6 is good for Black but arguably less so than the game.

In the diagram, 19 b4 fails to Bxf2+! 20 Rxf2 Nf6 when if

a) 21 Qh6 Qxf2+! 22 Kh1 (22 Kxf2 Ng4+) Ng8!; or

b) 21 Qg5 Ng4 22 Nh5 Qg6! wins material - but not 22 ...Qxf2+?? 23 Kh1 Rg8 24 Qxg8+ Kxg8 25 Re8 mate!

Short won queen for rook but 21 ...Bd7 was simpler, when White must try 22 Nxf5 Bxf5 23 Qxf5, and he then missed the splendid 24 ...Be7!! 25 Rxe7 Be6 trapping the rook.

The black king got caught in the middle, and due to the threat of 32 Rd5 mate he had to jettison the rook; in time pressure his game then fell apart.

White: Alexei Shirov

Black: Nigel Short

Las Vegas 1999

(Round 4 Game 1)

French Defence

1 e4 e6

2 d4 d5

3 Nc3 Nf6

4 Bg5 dxe4

5 Nxe4 Be7

6 Bxf6 gxf6

7 Nf3 Nd7

8 Bc4 c5

9 0-0 0-0

10 Re1 Nb6

11 Bf1 cxd4

12 Nxd4 Kh8

13 c3 e5

14 Qh5 Nd5

15 Rad1 exd4

16 Rxd4 f5

17 Ng3 Bc5

18 Rd2 Qb6

(see diagram) 19 Qe2 Nf6

20 Qe5 Kg8

21 h3 Re8

22 Qxe8+ Nxe8

23 Rxe8+ Kg7

24 b4 Qc6

25 Rdd8 Bb6

26 Rg8+ Kf6

27 Nh5+ Ke5

28 Rd3 Qh6

29 Be2 Qc1+

30 Rd1 Qxc3

31 Bf3 Be6

32 Rxa8 Qxb4

33 Re8 Bd4

34 Rd8 Bb6

35 a3 Qa5

36 R8d2 f4

37 Bg4! Bc4

38 Re1+ Be3

39 Rdd1 Bb3

40 Rb1 Bc2

41 Rb4 f5

42 Bf3 Be4

43 fxe3 Bxf3

44 gxf3 Qxa3

45 Nxf4! b6

46 Rd4