At the weekly duplicate the local club maestro got into stormy weather when his partner bid him up as declarer in 7 NT. Looking at all 4 hands it would be wiser to bid 7♥ where you can ruff a spade or a diamond for an easy make.
West led the ten of diamonds. The Maestro took his regular view. The number of tricks was not enough! He could only come to 12 counting 2 ♠, 5♥, 3♦ and 2 ♣. If diamond split 3-3 it was an easy make, if not he would need a squeeze to help him.
The maestro took the ace of diamonds. When he also played king and queen east discarded a low club as encouraging, north a spade.
When the Maestro ran the hearts leaving one, east appeared with a 4-card suit. West discarded two clubs and a spade. Declarer cashed the ace and king of clubs leaving this position
It was a perfect plot for a squeeze. East guarded clubs, west diamonds and both spades.
Dummy played the nine of hearts and east had to discard a spade to guard the clubs. South discarded a club and west was finished. He had to keep his diamond and discarded a spade.
The Maestro took the last three tricks with the king, ace and nine of spades making his Grandslam!
Do you see where the defense messed up?
It was indeed a difficult defense. East naturally encouraged in clubs holding the queen, this led to west discarding clubs on the hearts.
West feared that south had 3-card spade suit when he kept his jack –fourth.
If west had kept the clubs and discarded his spades, t would have broken the squeeze since west discard after south!
West knows he is done if south have K x x in spades, so he needs east to hold Q x x. The only defense to escape the squeeze is therefore to guard the clubs so east can discard his clubs on the fifth heart!
If so, the position would have been like this
As you see east can keep his D x x in spades and discard a club. West just discard the same as south and there is only 12 tricks on for declarer.
Not too tough to figure out?