Puzzle #12

February 1950 inferential problem

To the best of our knowledge, the earliest inferential problems were authored by the late Terence Reese and appeared in The Bridge World. We present one from the February, 1950, issue here, boiled down to its essentials.

 NORTH ♠ 8 5 2 ♥ J 6 ♦ K 6 5 3 2 ♣ 8 6 5 WEST ♠ K J 9 6 ♥ K 7 ♦ J 9 4 ♣ Q 9 4 2

West led the spade six against South's contract of three notrump. East won with the ace and returned the four; West won the jack and king of spades as all followed. At this point, if West leads the thirteenth spade the contract can be made against any defense, but if West leads any other card to trick four the contract can be defeated. What was South's hand?

#### Solutions

If the thirteenth spade merely adjusted the count for a squeeze, it could not make enough of a difference to meet the stated condition. It must also allow declarer to unblock diamonds. South's diamonds must be exactly A-Q-8-7 (not A-Q-10-8, else a diamond lead would resolve the block and lead to a strip-squeeze against West). After the fourth spade lead, declarer's ninth trick must come from a heart-club squeeze against West. Therefore, declarer's hearts are ace-queen doubleton (not more than doubleton, else the heart-king shift would not defeat the contract). South's clubs must be A-K-7-3, because if South's third highest club were as high as the ten, the club-queen shift would give declarer three club tricks and an endplay possibility.
After West leads the fourth round of spades, declarer can make the contract by discarding a heart from dummy and a diamond from the closed hand. Then, ace-king of clubs and five diamonds squeeze West between the rounded suits.