Except, declarer on the deal above overlooked a tactical nuance.
South opened One Heart and North started a delayed game raise with Two Clubs. However, East pre-empted with Four Spades and after two passes North felt impelled to show his heart support. Five Hearts was passed out although West gave consideration to sacrificing.
West led the ace of spades and declarer ruffed the spade continuation. He laid down the ace of hearts and East followed with the jack. The next trump lead saw West following with the nine and decision time had come. In view of East's known length in spades the odds on the heart finesse looked even better than usual and South was visibly distressed when East won with the queen. He became even more distressed when the diamond finesse failed as well to leave him with only ten tricks.
What declarer failed to take into consideration was that, if going up with dummy's king of trumps failed to drop the queen, he was still home and dry, irrespective of whether the diamond finesse was right or wrong.
Suppose East shows out on the king of hearts - declarer follows with his five club winners, discarding diamonds from hand, then exits with a trump to West's queen. On lead, West has now the choice of leading a diamond or conceding a ruff and discard.
North S. 6 2 H. K 10 8 4 D. 6 3 C. A K J 10 3 South S. 8 H. A 7 6 5 3 D. A Q 9 8 5 C. Q 5 West S. A 3 H. 9 2 D. K J 7 2 C. 9 7 6 4 2 East S. K Q J 10 9 7 5 4 H. Q J D. 10 4 C. 8Reuse content