Vienna Coup

"The Vienna Coup is really a simple squeeze. However, before it can operate, declarer must play off a winner or winners in a suit to set up a lower-ranking card in the correct position as a threat.

"After South's weak jump overcall, North could count 10 or 11 tricks with the help of a spade ruff. Since where there are 11 sure tricks a 12th can frequently be developed, North wasted no time in getting to slam.

"West led [the ten of spades], East won and, for want of anything better, shifted to the queen of diamonds. There were only 11 top tricks - the 12th would have to come either from ruffing out the king-jack of clubs or a squeeze. Since East almost surely had the king of clubs and the defense virtually marked him with the jack of diamonds, declarer chose the squeeze as the surer line. However, East would be discarding after dummy, so a threat card had to be set up in the South hand.

"Declarer won the diamond in dummy, came to hand with a trump and ruffed a spade. After drawing the last trump, declarer cashed his remaining high diamond and then started to run trumps. When he led his last heart, the table was down to a diamond and the ace-10 of clubs, and East held the jack of diamonds and king-jack of clubs. Dummy parted with its diamond, but East was caught in a vice. As the cards lie, he had to hold onto both of his clubs or else dummy's 10 would be the fulfilling trick, and his jack of diamonds was needed to prevent declarer's 10 from scoring. No matter what he chose to discard, he would be presenting declarer with his slam."

"West took the king and queen of spades and shifted to the queen of diamonds. As usual in squeeze situations South could count 10 tricks but needed 11.

"West was marked with the jack of diamonds and almost surely with the king of hearts so the squeeze had to be against him.

"If South simply ran out dummy's trump suit he would have to discard before West and would not be able to hold on to his threat cards so the Vienna Coup became necessary.

"After drawing a couple rounds of trumps he cashed his ace of hearts and then ran the rest of the trump suit.

"He was able to discard his three low hearts on dummy's clubs but see what happened to West.

"He had to hold on to that king of hearts and eventually was forced to unguard the jack of diamonds whereupon South's king and ten of diamonds were good for the last two tricks."