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, the Dutch titleholder programmed by Hans Kuijf, won the final by 1 imp. The
result hinged on the very last deal, on which WBridge5 from France had a
chance to tie the match 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 rebid 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. In that case however North would become declarer
and the contract was doomed after the lead of a low spade.
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 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 it was very difficult for East to 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.