Bennett Cerf, one of the founders of Random House, said, “Middle age is when your old classmates are so gray and wrinkled and bald that they don’t recognize you.”

One reason bridge experts make fewer mistakes than other players is recognition. They recognize situations and know the right bid or play to make almost subconsciously.

Both South and East can make expert plays in this deal. South reaches four hearts, and West leads the club king to declarer’s ace. What might happen after that?

Three diamonds was a help-suit game-try, which North accepted with all of his points in the red suits.

Declarer, at trick two, ran the heart 10. East realized that there was scant chance to defeat the contract, given that he had the diamond king presumably sitting under South’s ace. So, East tried a ruse. He won with his heart ace and shifted to the diamond three.

Now move into declarer’s seat. What if this shift was a singleton? Then, to take a losing finesse would cost the contract because the defenders would take the heart ace, the diamond king, a diamond ruff and the club queen. But with West “clearly” having the heart queen, it was “safe” to win with the diamond ace and repeat the heart finesse.

Imagine South’s shock when East produced the heart queen, cashed the diamond king, and led a club to West’s queen for down one.

A more skillful South would have led a low heart to dummy’s jack, not run the 10. Then East could not have afforded to win with the ace for fear that West had started with 10-doubleton.