Ending Foreseen

Dlr: South ♠ 7 5 4 2
Vul: None 9
A K
♣ K 9 7 5 4 2
♠ A Q 6
A 3
Q 9 5 2
♣ A Q 6 3
West North East South
1♣
2♣ (1) 2(2) 4 4♠
Pass 6♣ All Pass

(1) 2♣: at least 5-5 in the majors
(2) 2: Limit raise or better in clubs
Against your slam, West leads the K. How will you get to 12 tricks on this deal?

Solution

Declarer could count 11 tricks and saw that, as the spades were undoubtedly 5-1, the 12th trick would have to come from an elimination and endplay. Accordingly, declarer won the first trick with the A and ruffed the 3 at trick two. Declarer continued with a low trump to the ace. After West discarded a heart, declarer continued by cashing dummy’s diamonds. This was a safe maneuver. The auction indicated that 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 dummy, 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, he played the 6 from his hand. This gave the defenders no winning option. West had discarded the ♠10 earlier, so he could allow the ♠9 to hold, East had only hearts left, so he had to lead one. Declarer threw the ♠Q from his hand and ruffed in dummy for his 10th trick. His hand was now high with a trump and the ♠A. Of course, if West had overtaken the ♠9, he 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. The full deal:

Dlr: South ♠ 7 5 4 2
Vul: None 9
A K
♣ K 9 7 5 4 2
♠ K J 10 8 3 ♠ 9
K Q J 6 2 10 8 7 5 4
J 8 3 10 7 6 4
♣ — ♣ J 10 8
♠ A Q 6
A 3
Q 9 5 2
♣ A Q 6 3