September 26, 2002
Computers That Gamble And Imagine
he closest result in the World Championships in Montreal a month ago went virtually unnoticed. It came in the annual World Computer Championship, organized by Alvin Levy of Stony Brook, N.Y., in which Jack, a Dutch program devised by Hans Kuijf, won the final by 1 imp. The result hinged on the last deal, on which WBridge5 from France had a chance to make the match a tie by scoring an overtrick. Other programs were entered from Britain, Germany and Japan and two from the United States.
Judging by the deals in the final, the gap between bridge computer programs and human players is rapidly narrowing. On the deal shown, WBridge5 opened the North hand with one club and jumped to three clubs when its partner made a negative double of one spade.
If computers can be said to gamble, South gambled by bidding three no-trump. It was likely that North held a spade honor, but a human might well have bid three spades. That would have led to a three no-trump contract from the North side, due for defeat after a low spade lead.
But three no-trump from the South side was tricky. It was necessary for the defense to establish spades, but the routine lead of the spade seven would have blocked the suit fatally. Whatever East did after dummy played low, the defense would have been unable to run the spades after South established clubs.
There were only two effective leads. One was the queen, an unconventional move that could have been fatal with a different spade layout. The other was the nine, which unblocked the suit. Jack as West found this imaginative lead, showing a quality not usually associated with computers.
But East could not read the situation. Instead of ducking when dummy played low, and preparing to run the suit by cashing the ace with West unblocking the queen, East took the ace and shifted to a diamond. East presumably thought that the nine was West's highest spade, and was hoping that its partner held K 10 x x of diamonds. That might have been the situation, but in practice South was able to establish clubs and make 11 tricks.
In the replay, Jack again showed imagination by jumping to four hearts as North when its partner showed some heart length with the negative double. This was likely to be a 3-4 fit, and it was. The contract offered multiple chances, and made with an overtrick after a diamond lead, the cards lying favorably. No imps changed hands, but both programs had performed creditably.