I continue a series on end plays: giving an opponent the lead in a position where he can't lead safely. You may not be able to guarantee eliminating all of an opponent's safe exit cards, but a good declarer does what he can.
West led the ace and deuce of diamonds against four hearts, putting South at risk of three more losers: a diamond ruff, a trump and a spade. But South ignored the danger: He led a trump from dummy next, captured East's king and led another trump.
East won and returned a diamond, and West ruffed and exited with a club. Declarer won in dummy and let the queen of spades ride, but West took the king. Down one.
South can't avoid the diamond ruff, but he can eliminate West's safe leads after he ruffs. After South takes the ace of trumps, he takes the A-K of clubs and ruffs a club.
South then leads a second trump. East wins and gives West a diamond ruff, but West has only spades left and must lead from his king, conceding the contract.

You hold: K 9 8 5 3 T 5 3 2 A 2 J 8 6. Your partner opens one diamond, you respond one spade and he bids two clubs. What do you say?
A: Your partner has five or more diamonds but maybe only four clubs. He wouldn't bid this way with 4 2, A 8 7, K J 7 6, K Q 5 4. Bid two diamonds. He should do better at a 5-2 diamond fit than at a 4-3 club fit. Moreover, game is still possible, and a "false preference" will give partner another chance if he has a strong hand.
North dealer
Both sides vulnerable

T J 10 7
K Q 7 4
A K 5 3

K 9 8 5 3 10 4 2
T 5 3 2 T K Q
A 2 J 10 9 5
J 8 6 Q 10 7 2

A 7 6
T A 9 8 6 4
8 6 3
9 4

North East South West
1 NT Pass 2 Pass
2 Pass 2 T Pass
4 T All Pass
Opening lead - A