The auction in this hand was simple. North knew his side had 33 to 35 hcp between them so small slam was on and a grand slam was not. Often one investigates for a suit slam but North’s only four card suit was weak and a cardinal rule is that one does not introduce weak suits in a slam auction.
West led the jack of spades. Declarer could count eleven tricks and, at first glance, the contract seemed to depend on hearts being 3-3. Declarer was a bit surprised when East discarded a diamond on the spade lead. After winning the first trick with dummy’s king of spades, declarer cashed the king, jack and ace of clubs.
When the suit broke 3-3, ten of West’s cards were known. So, declarer ducked a heart since it was necessary to lose a heart even if they were 3-3. After winning West’s spade return in dummy with the ace, declarer cashed the king of hearts and the king of diamonds. When West followed to both, declarer had a complete count of the unseen hands: West had started with 7=2=1=3 shape and East with 0=4=6=3. EW vul, Dealer South
Declarer cashed the queen of spades and the end position is shown in the next diagram.
When the queen of clubs was led, declarer discarded a diamond from dummy, and East had no answer.
Whichever suit he discarded from would see declarer cash the ace in that suit and use the ace in the other suit to reach the established red-suit winner.
This is a simple squeeze with a slightly exotic arrangement of entries and is called a criss-cross squeeze. Since it will work against either opponent, it is an automatic squeeze.