The backward finesse is a play seldom used by declarer. The proper setting for it occurs so rarely, and the play itself is so unnatural, that it is virtually a collector’s item.

First let’s define what is meant by a backward finesse. Usually, if declarer has the diamond combination shown in the diagram, he cashes the king and then plays a diamond to the jack. If East has the queen, the finesse wins, and South makes three diamond tricks. In the absence of clues indicating otherwise, South has about a 50% chance of winning the finesse.

Note that declarer would make only two diamond tricks in the actual deal, and would therefore go down one, if he played the suit in the usual way. But note also that South can win three diamond tricks by first leading the jack from his hand. Leading an unsupported jack is contrary to the canons of good card play, but it is undeniably effective in the present case.

If West ducks the jack, South scores three diamond tricks. If West covers the jack, declarer takes the king, leads a diamond to the nine and again has three diamond tricks.

The backward finesse is rarely used because it requires two cards to be favorably placed, while a simple finesse requires only one. The odds against a backward finesse succeeding are ordinarily 3-1.

Nevertheless, the backward finesse is the right play in this deal. When South ruffs the third round of spades and leads a trump, East turns up with the ace. Since East passed his partner’s opening bid, declarer should conclude that East does not also have the queen of diamonds.

Accordingly, after drawing trump and cashing the A-Q-K of clubs, South leads the jack of diamonds, knowing that West has the queen and hoping that East has the ten. In the actual deal, the backward finesse succeeds, and South makes the contract.

Tomorrow >> Famous Hand.

— Steve Becker King Features