Source: IBPA Bulletin Dic. 2017 Dealer North E/W Vul
10 8 7 A 7 K Q J 10 Q 10 6 4
Q J 4 2 9 4 9 6 4 3 A K 9 10 8 5 3 2 8 2 J 8 7 5 3 2
A K 9 6 5 3 K Q J 6 A 7 5
West North East South
1 Pass 1
Pass 1NT Pass 2
Pass 2 Pass 6
Pass Pass Pass
Opening lead: A West led the ace of clubs. Declarer ruffed and played the ace of trumps. All would have been well if East had followed suit; declarer would have had twelve easy tricks. However, East’s club discard reduced declarer to needing a trump endplay to bring the contract home. The first requirement was that declarer needed West to have three clubs, because he needed to reduce his trump length as West followed suit. As will be seen, in the endgame, declarer needed to have two trumps and a good heart and West three trumps. The specifics in the red suits were a little different in that, once the assumption in clubs was fulfilled, declarer could have made twelve tricks at double dummy if West had held 2=4, 3=3 or 4=2 in the red suits. However, this was a single dummy problem. So, as playing three rounds of diamonds would work in the first two cases, declarer did just that. When East discarded on the third round of diamonds, declarer cashed the remaining diamond winner and threw a heart from hand. After ruffing a club, declarer played a heart to the ace and ruffed another club. After cashing the king of hearts, declarer held the king-nine of spades and the queen of hearts; West held the queen-jack-four of spades; dummy had the ten-eight of spades and the queen of clubs. When declarer led the queen of hearts, West was skewered: if he had ruffed high, declarer would have made the last two tricks with trumps and, if he had ruffed low, declarer would have scored a trump in dummy and the king of trumps to make his contract. You should note that if West had had four clubs and two hearts, he could have avoided the trump endplay by ruffing the third heart and exiting with a club.