After West continued with a heart to East, declarer saw that he could always make 10 tricks provided the diamonds were 3-2 and neither defender could get a club ruff. Declarer decided to play on those assumptions, which pointed to his best route to 10 tricks. His first move was to ruff the ♥10. Next, he led a club to dummy’s king. East took this with the ace and, hoping to cause South a problem, played a third heart. After ruffing this with the ♠8, declarer cashed his three minor-suit winners and then played a third round of diamonds. Declarer had already made five tricks, so West had no winning defense after he won the ♦Q. West took his best shot by exiting with the *S*9, Declarer played low from dummy and won the trick with the ♠J, his sixth trick. Declarer could now win the next four tricks on a high crossruff.
Notice that if East had returned a trump after winning with the ♣A, declarer could have cashed dummy’s ♣Q then played the ♦A, ♦K and another diamond. As West would not have a trump to play, declarer would have been able to ruff the card West played, then crossruff the last four tricks. Finally, if West did have a trump and played it, declarer could draw trumps and claim the rest. The full deal:
