One of the novels of Charles Dickens included a comment on the snobbery of Victorian England in relation to cardplaying. "He calls the knaves jacks, this boy," Estella said of Pip in "Great Expectations." But "this boy" had the last laugh. Even in England, the word knave is obsolescent, used only by the very old or those being consciously quaint.

The great novelist would be astonished by a current meaning of the word jack. With a capital letter, it is the name of the Dutch computer program that has won the world computer bridge championship for four straight years. It is the brainchild of Hans Kuijf, with input from Wim Heemskerk, Martin Pattenier and a former world champion, Berry Westra. (Information at www .jackbridge.com.)

In the 2004 contest, staged at the Summer Nationals in Manhattan two weeks ago, Jack defeated an American program, Bridge Baron, in the final by 60 imps. The diagramed deal is from the semifinal against a French entry.

Jack's bidding with the North-South cards was highly sophisticated. Jack-North reversed with two diamonds, indicating great strength. It then rebid three clubs, suggesting 4-6 distribution in the minor suits. Jack-South took over, leaping to four no-trump, Roman Keycard Blackwood.

With clubs agreed, the response showed two keycards plus the trump queen. Five no-trump, asking for the number of side kings, was clever. Jack-South intended to pass six clubs, which would have been the right contract if North had held slightly different red suits: a doubleton heart queen with A-Q-x-x in diamonds.

As it was, six no-trump was the perfect contract, with the heart king protected against a lead in that suit. When West led the spade jack, South could claim all of the tricks.

In the replay, the opposing program had a bidding failure. South responded two spades to one club and rebid its spade suit after three diamonds. North then bid three no-trump, a poor choice for two reasons: A heart stopper was lacking, and there were good slam prospects.

Jack-East rejected the standard lead of the heart four, seeing the danger of a blockage. It produced the heart ten, the key move, after simulating some possible layouts. It could now hold the lead if the declarer played low from the dummy, and the defense took the first five tricks for down one.

The best computer programs are improving constantly and can now play against midlevel humans on equal terms. Jack's creators feel that it is still weak in defense, but one would not suspect that in view of the lead of the heart ten.