"I'm back in business." Garry Kasparov's most positive pronouncement for three weeks came after he had demolished Viswanathan Anand to equalise the scores at the half-way stage of the PCA world championship. His win was a remarkable triumph of pre-game preparation.

The first 13 moves were identical to those of the sixth game, but this time Kasparov unleashed a brilliant new idea. With 14.Bc2! sacrificing a pawn, and 15.Nb3!! offering a rook, he gave Black no time to get his king into safety. If Black takes the bait with 16...Qxa1, then 17.Qf3 wins back a good chunk of the material, while maintaining a powerful attack.

Anand delayed taking the rook for one move, but it quickly became clear this had also been foreseen in Kasparov's analyses. After 18.Bxe6, White threatens a devastating attack beginning with 19.Bd7+. Anand's reply met with ano-ther powerful blow, 19.Bh6!! which Kasparov banged down on the board, before going off to his rest room and slamming the door.

If Black plays 19...gxh6, he is mated by 20.Qh5+ Ke7 21.Qf7. Anand's queen scampered back to the defence, but after 21.Bxh8 the final point of Kasparov's idea was revealed: 21...Ne2+ 22.Kh1 Ng3+ 23.hxg3 Qxf1+ 24.Kh2 Qxf2 25.Bf6 would leave Black again defenceless.

Kasparov had played his first 21 moves in only five minutes. Anand had thought for over 45 minutes on move 15 alone. And White already had a totally winning position.

Anand must feel that he lost the game without ever having had a chance to play. It was all decided back in Kasparov's hotel suite. Now the Indian challenger's team of seconds must work hard to patch up his the gaping hole left in his main defence to 1.e4.

Kasparov-Anand: Game 10

1 e4 e5 20 Bxg7 Qd3

2 Nf3 Nc6 21 Bxh8 Qg6

3 Bb5 a6 22 Bf6 Be7

4 Ba4 Nf6 23 Bxe7 Qxg4

5 0-0 Nxe4 24 Bxg4 Kxe7

6 d4 b5 25 Rc1 c6

7 Bb3 d5 26 f4 a5

8 dxe5 Be6 27 Kf2 a4

9 Nd2 Nc5 28 Ke3 b4

10 c3 d4 29 Bd1 a3

11 Ng5 dxc3 30 g4 Rd5

12 Nxe6 fxe6 31 Rc4 c5

13 bxc3 Qd3 32 Ke4 Rd8

14 Bc2 Qxc3 33 Rxc5 Ne6

15 Nb3 Nxb3 34 Rd5 Rc8

16 Bxb3 Nd4 35 f5 Rc4+

17 Qg4 Qxa1 36 Ke3 Nc5

18 Bxe6 Rd8 37 g5 Rc1

19 Bh6 Qc3 38 Rd6 resigns