1. At least 5-5 in hearts and spades
2. Limit raise or better in clubs
West leads the West leads the ♥K against your slam and when dummy comes down you can count 11 tricks. How will you get number 12?
After winning the opening lead in hand, declarer could see that the spades were undoubtedly 5-1, so the 12th trick would have to come from an elimination endplay.
So, at trick two, declarer ruffed the ♥3 in dummy, followed by a low low trump to the ace. After West discarded a heart, declarer continued by cashing dummy’s ♦A and ♦K This was a safe maneuver because, from the auction, declarer knew West had at least 10 cards in the majors and so at most three diamonds, giving East at least four cards in the suit.
Next, declarer drew East’s remaining trumps with dummy’s king and his queen. After cashing the ♦Q, throwing a spade from table, declarer ruffed the ♦9 in dummy, eliminating that suit. As West had three diamonds, his original shape had to be 5=5=3=0. Declarer led a spade from dummy, and when East played the 9, declarer played the 6 from his hand. This gave the defenders no winning option.
West had discarded the ♠10 earlier, so declarer allowed the ♠9 to hold. East, however, had only had hearts left, so he had to lead one. Declarer threw the ♠Q from his hand and ruffed in dummy for his tenth trick. His hand was now high, with a trump and the ♠A. The full deal:
Of course, if West had overtaken the ♠9, she could avoid conceding a ruff-and-discard only by leading a spade, giving declarer the two spade tricks needed for his contract.
Finally, there was an alternative endplay: declarer could have cashed the ♠A before endplaying East with a diamond to get a forced heart return with the same result as occurred at the table in practice.