Shout when you see the King

On this deal from the World Championships in Bali, I want you to shout out when, declaring 4♥ as South, you can deduce where the missing king of clubs lies. Study the auction first – right from the very beginning.

West leads the five of diamonds and...

Can I hear you shout? You should know already where that king of clubs lies. Here is how. West would lead a top spade holding ace and king, therefore East has either the king or ace of spades. 

West would lead a high diamond if he holds a sequence and would not lead away from the ace; therefore West is leading from the king or queen and East holds acequeen or ace-king. Together with East’s top spade, there is no room for East to hold the king of clubs, or he would have opened the bidding. Ergo, West holds the king of clubs. 

East wins trick one with the ace of diamonds and leads a second diamond (the spades can wait). Declarer ruffs, draws trumps in three rounds (East with one), then cashes the ace of clubs, spurning the finesse. [If he wishes, he canlead the jack of clubs from dummy and flamboyantly rise with his ace – he can always finesse against East’s nine later, reaching dummy by ruffing the third spade].

West’s king of clubs delightfully falls under your ace and you can cash your three promoted clubs and merely give up two spades. 10 tricks and game made.

You did not know that West’sking of clubs was singleton – only that he held the card, rendering the finesse pointless. Or perhaps you did start to suspect it was singleton... 

West must have six spades – if he holds five, East has three and would have supported in the auction. East would not volunteer 3 ♦ without six cards, so West has three. When you draw trumps, you discover West holds three. That leaves room for just one club...the king.

Elementary, my dear Watson.