The principle of not looking a gift horse in the mouth can easily be extended to contract bridge. Essentially, if the opponents give you a chance to make a contract you’re not entitled to make, you grab it with open arms.

First, a word about the bidding. North was obviously not a product of the scientific school of bidding. He certainly had good support for diamonds, but the leap to six enormously overstated his values. He would have done better to suggest a slam by jump-shifting in clubs and supporting diamonds later, or, for those who play it, via a splinter bid in spades, but neither of these would have engendered much interest from South.

North’s optimism was rewarded, however, when West chose a heart as his opening lead. With any other lead, the slam would have failed.

Declarer had a critical problem to solve at trick one. The question was whether to play the ten or the queen from dummy. He chose the queen and made the contract, but the reasoning behind the play of the queen is worthy of study.

Obviously, the card played is immaterial if either defender holds the K-J. If West has both honors, either play is successful; if East has both honors, either play fails.

South’s choice matters only when West has the king and East the jack, in which case the queen is the winning play, or when West has the jack and East the king, in which case playing the ten wins. The only tangible clues to guide declarer are the bidding and the opening lead.

South can reasonably assume that if West held the A-K of spades, he would have led one of them. Declarer should therefore conclude that West has only one of the top spades and so is a strong favorite to have the king of hearts for his overcall. So, South plays the queen and makes the slam.

Tomorrow: When to violate a sacred rule.