Finesse or Drop Test

There was a strikingly good example of the importance of “retaining the finesse position” on this slam deal. Correct technique gained not one but two tricks in the key suit - diamonds. Seeking to avoid losing to the missing queen of diamonds, the odds favour taking a finesse.

However that is not the end of the story - as one declarer found to his cost. West led a heart to East’s ace, and East hopefully tried to cash the ace of clubs. After trumping the club and cashing the ace of trumps (both following), declarer led a diamond to dummy’s jack. Oops. East won his singleton queen, and now declarer could not avoid losing a second diamond trick to West (his ten-nine-seven ensuring that he had a fourth-round winner). Down two.

Correct technique in the diamond suit involves retaining the finesse position - dummy’s king-jack - until the second round. After ruffing the club and drawing trumps, declarer cashes his ace of diamonds (key play). When he sees East’s queen drop, he deduces that West has all the remaining diamonds. He therefore leads a second diamond, and when West plays low, inserts dummy’s eight. East duly discards, so he cashes the king-jack of diamonds, crosses to the king of hearts, and reveals his hand (all trumps). 12 tricks and slam made.

Note that if West played the nine of diamonds on the second round, declarer would win dummy’s jack, cross back to hand, then finesse West’s ten of diamonds, dummy holding king-eight over West’s ten-seven.