Test your defensive play
You are West, defending against Four Spades, and this is what you see after leading the king of hearts:
South wins your king-of-hearts lead with the ace, East playing the five, and cashes the A-K-10 of spades, East following with the 4-2-6. On a low club lead from dummy, East plays the four and declarer the king. How would you defend? *** You have to don your thinking cap securely for this one. The first problem is whether to win the club, but before deciding this, you should try to work out what kind of hand declarer must hold for the contract to be defeated. You start by brushing aside those hands where the contract is indefensible. You can’t win by conceding defeat. All your thoughts should be focused on hands where South might have four losers. You know from the bidding and East’s high-low in trumps (indicating three of them) that South started with six trumps. He therefore has 10 tricks – six spades, two clubs, a heart and a diamond – after you take the ace of clubs, assuming you give him a chance to cash them.
However, you may be able to score four tricks before South can score 10 -- if the cards are divided as you must hope they are. Since you are obviously limited to one trick in clubs and one in diamonds, your only chance is to win two heart tricks. This is possible in only one case, namely, if East started with specifically the J-5 of hearts. Since this is your only hope, you should defend on that basis. Accordingly, you win the club at trick five and return a low heart. You are rewarded when East wins with the jack and returns a diamond to your ace, and you cash the queen of hearts to set the contract.
In the actual deal, South had ♠ QJ9873 A82 ] Q5 K3 and was ♥ ♦ ♣ defeated by the low heart return.