The 64-board final of the 13th World Computer-Bridge Championship, played in Washington last month, was close throughout. With 16 deals to go, Jack from the Netherlands led Wbridge5 from France by 85 international match points to 79.
Wbridge5 closed the gap to 2 imps with five boards to be played. On Board 60 Wbridge5 overbid to a hopeless three no-trump to lose 5 imps. After a flat board, Wbridge5 misdefended to allow a second overtrick in three no-trump. That cost 1 imp who cares about 1 imp? The margin was 8 imps when the diagramed deal, Board 63, was played.
Look at the South hand. You pass, and partner opens one heart. How would you plan the auction?
If you knew partner did not have spade support, you would respond one no-trump, planning to rebid in diamonds. But understandably both programs responded one spade. Now, though, over North’s two-club rebid, they were in an awkward position. How do you and your partner treat a two-diamond rebid?
If South were not a passed hand, two diamonds would be fourth-suit game-forcing. South would have no good rebid. And although South is a passed hand, many experts still treat it as an artificial one-round force. But both computer programs played it as natural.
Jack North then tried for game with two no-trump before respecting his partner’s signoff in three diamonds.
Wbridge5 West did well to lead a trump, but Jack South played on spades to bring home an overtrick.
At the other table over two diamonds, Wbridge5 North jumped to three no-trump. If Wbridge5 South had been taught that three no-trump ends all auctions, it would have passed. Then, with the aid of two winning minor-suit finesses and a favorable diamond break, that contract would have rolled home, gaining 7 imps for Wbridge5 and leaving the match hanging by 1 imp with one board to go. But Wbridge5 South removed to four diamonds, and Wbridge5 North raised to five diamonds.
Jack West also accurately led a trump. Declarer won in hand, cashed the heart ace, played a diamond to dummy’s ace and ran the heart queen, losing to West’s king. West now shifted to spades, giving the defense one heart and three spades for down two.
Plus 130 and plus 100 gave Jack 6 imps. And when the last board was flat, Jack had won by 14 imps.
However, if Wbridge5 had made three no-trump on the diagramed deal, it would have gained 7 imps and lost by 1 the value of that unnecessary overtrick.
Also, did you notice that four spades is makable in this deal?
Over the last nine championships, Jack has won six times and Wbridge5 three. Full details can be found at the Web site of the championship organizer, Al Levy, ny-bridge.com/allevy/computerbridge.