Assume you reach seven hearts on the bidding shown and West leads the ace of clubs, which you ruff. The contract seems very easy to make; the only conceivable complication is the possibility that one defender might have all four missing diamonds.

You begin by drawing trump, West turning up with three and East only one. You then have to decide whether it’s better to start the diamond suit by first cashing the king or the ace. (Remember, you are assuming a 4-0 division because if the suit is divided 3-1 or 2-2, the grand slam is cold.)

To settle the question beyond the shadow of a doubt, you next cash the ace of spades, and when everyone follows suit, you know that playing a low diamond to the ace is certain to bring home the grand slam.

This is because West cannot have less than a six-card suit for his vulnerable three-club bid, and since he has already shown up with three hearts and a spade, he cannot hold four diamonds.

Sure enough, when you lead the diamond six to the ace, West shows out. You then continue with the deuce and trap East’s J-9-5, whatever he does. If he plays the five, you finesse the seven; if he plays the nine instead, you win with the king, cross to the queen of spades and return the four of diamonds, gobbling up East’s J-5 with your Q-7.

Ordinarily, when you hold K-Q-x-x opposite A-10-x-x-x, you would cash the king first — and it would be easy to make that mistake here from force of habit. But in the present case — where you hold the seven and eight in the two hands and also have the benefit of West’s three-club bid — cashing the ace first is clearly the correct play.

Tomorrow: Bidding quiz.