Chess

Everybody who saw Deep Blue beating Garry Kasparov in the second game of their match earlier this week knew that they had witnessed something quite amazing, but the most amazing feature of the game emerged only some hours after it was over. The fact was that, for probably the first time in his life, Garry Kasparov had resigned a game in a drawn position.

The diagram shows the position. Black's queen is attacked by the white rook, and 1...Qxc6 2.dxc6 leaves him hopelessly placed. For example 2...Rc8 3.Ra5 or 2...Bc7 3.Ra7 Rc8 4.Bd5+ and 5.Be6. So Kasparov resigned - but he could have played 1...Qe3! 2.Qxd6 Re8!! when 3.Bf3 Qc1+ 4.Kf2 Qd2+ 5.Kg1 Qc1+ 6.Kh2 Qf4+ lets Black force a draw. One computer analysing this variation came up with 3.h4, when 3...Qxe4 loses to 4.Ra7+ Kf8 5.Qd7, and Black has no perpetual check, but more analysis produced 3...h5! as a saving resource for Black (the idea is to provide a saving check with the black queen on g4 at the end of a long variation many moves hence. Yesterday CJ Tan, one of Deep Blue's programming team, came out on stage while his machine was playing the third game to make the definitive pronouncement on 1...Qe3. They had fed the move to the computer to ask its opinion and, after several minutes' thought, the answer came back: 1...Qe3 is a draw.

Then, to rub in the message, Deep Blue recovered from a very poor position to salvage a draw itself in game three, thus keeping the scores level at the halfway point of the match. So far, Garry Kasparov has won one game, lost a game that he should have drawn, and drawn one that he should have won. It's a tough life being human.

Tomorrow's column will include the full moves of game three and the result of the fourth game.