What is the key to the key suit?

Vauvenargues, who was a French moralist, stated that great thoughts come from the heart. Presumably he felt that thoughts and emotions are interconnected. However, at the bridge table we should try to stop our emotions from clouding our thoughts, our judgment.

In today’s deal, South spotted the critical snippet of information that provided the key to success. Against the contract of three no-trump, West led the heart five. What was South’s plan?

First, he tried dummy’s heart jack; West might have underled the heart king-queen. However, East produced the queen. It would have been nice to duck two rounds of hearts, trying to cater to a 5-3 division where East holds the diamond ace. But South realized if TEXT he did that and they switched to spades, he would almost certainly fall to defeat, losing one diamond, two hearts and at least two spades.

So South won the first trick and immediately played on diamonds.

East won with his ace, and the defenders took their three heart tricks before exiting in spades.

South took his diamond winners, learning that West had a singleton. Then declarer cashed dummy’s club ace, played a club to his king and finessed dummy’s club 10 successfully to land the contract.

“Nice guess,” said North. “Not really,” explained South. “I knew West had started with four hearts and one diamond. If he had five spades and three clubs, surely he would have led a spade, not a heart. He must have had four cards in each black suit and an initial 4=4=1=4 distribution. Hence my play in clubs.”