Intermediate and newcomer players - sharpen your game with this series of tutorials. You can browse the index by topic, or read them in order. Learn even more at ACBL's Learn page.
Against 4♥, West led the ♦K, won by Declarer’s Ace. Assuming that Clubs were breaking 3-2, and by taking a Diamond ruff in Dummy, Declarer could count 10 tricks (5 trump winners, ♦A and a Diamond ruff, and 3 Clubs). The only losers would be a Spade, the ♥K, and a Club.
A pretty simple hand, eh? Well, not exactly! Declarer won the Diamond opening lead, ruffed a Diamond in Dummy, and cashed the ♥A. Declarer needed to get back to hand in order to draw trumps, and that would have to be done with a ruff. So he lost a Spade, ruffed the Diamond return, and played the ♥Q, driving out East’s King. But, with West showing out of Hearts on the second round, and with East returning yet another Diamond, Declarer’s goose was cooked. He could ruff the Diamond and draw East’s remaining trumps, but then would be out of trumps himself. When he later lost the third round of Clubs, the defense would cash a Spade for down one. Declarer lost trump control with his line of play. He actually had two different ways to save the day. Do you see how?