Think in patterns

West led ♦ A which held the trick, East following with ♦ 6. He followed with ♦ K, East playing ♦ 9. Hoping East had no ♦s remaining, West continued with ♦ 2. Dummy’s ♦ Q won and declarer discarded ♣ 4. He cashed ♥ AK, trumped ♥ 3 with ♠ 6 and so established his long ♠s; he then cashed his ♠ AK and claimed the remainder, conceding just one trick to ♠ Q. West could have defeated the contract by switching to a ♣ after cashing ♦ AK. How should he have known?

East had played first ♦ 6 then ♦ 9 under ♦ AK. If he had only held a doubleton ♦, he would signalled encouragement by playing first ♦ 9 then ♦ 6. So West should have known that it was declarer who held the doubleton ♦. Why should West have switched specifically to ♣s, looking at such strength in the dummy? Declarer had opened the bidding 1 ♠, then rebid ♥s. Such a sequence indicates 5-5 in the two suits, leaving just three other cards. Two of them have been revealed as ♦s, therefore he has a singleton ♣. West must lead a ♣ immediately or else declarer will discard it in dummy’s ♦ Q (as he did). East will win ♣ A and later score ♠ Q to defeat the contract.

ANDREW’S TIP: Work out declarer’s hand-pattern using clues from the bidding and the play to date.