Declarer’s objective in most deals is to make the contract, and if, in attempting to reach this goal, he goes down an extra trick while trying to do so, it should not really bother him.

Take this case where South is in four spades and West leads a club. East cashes the A-K and shifts to the queen of hearts. Declarer ducks the queen and wins the next heart with the ace.

South is now at the crossroads of the hand. He has a heart loser and must formulate a plan to get rid of it. The only way this can be done is to try to establish an extra diamond trick in dummy, which necessitates ruffing three of dummy’s diamonds and the suit being divided 4-3.

There is also another hitch. Dummy’s fifth diamond will be of no value to declarer if there is no entry to dummy to cash it. For this reason, declarer must adopt a somewhat unusual line of play.

At trick five, he leads a diamond to the ace, then ruffs a diamond high. He next leads the spade deuce and finesses the seven! When this wins, South ruffs another diamond high, then finesses the eight of spades. This is followed by a third diamond ruff high, after which dummy’s ten of spades provides the entry to cash the jack of diamonds and make the contract.

It is true that declarer risks going down an extra trick — 100 points — by finessing the spade seven on the first round of the suit. But it is also true that if the finesse succeeds and the diamonds are divided normally, he scores 620 points for making a vulnerable game. Since the finesse can gain a lot and lose only a little, it is clearly the right play.

Tomorrow: Test your play.