Marie Curie said, “There are sadistic scientists who hurry to hunt down errors instead of establishing the truth.”

In bridge articles, we often try to establish the truth by analyzing errors. Well, what error would often be made in this deal? South is in three no-trump, and West leads the spade queen.

The auctions have been short and sweet this week, today’s being the most common of all. (Some years ago, I was involved in two of the rarest sequences on backto back deals when the final contract on each was one club.)

South starts with seven top tricks: two spades, three hearts and two clubs. He can establish two more winners in diamonds, but risks losing the race if the defenders can first set up and run their spades.

South ducks the first trick, takes the second with dummy’s spade ace, and leads a diamond.

An East who is trained only to cover the last of touching honors, will play low. West can also duck the trick, but then South has two winning options: Lead another diamond, which would dislodge West’s entry; or play three rounds of clubs, which would establish a third winner there to go with two spades, three hearts and one diamond.

East should remember this key principle: In no-trump, when partner’s suit is one lead from being established, and you have only one card left in his suit, do your utmost to win the next defensive trick. East must play his diamond king at trick three. If South has the ace, the king is dead anyway. Here, though, when the king wins, East leads his last spade, and the contract is defeated.