Declarer can sometines keep a dangerous defender out of the lead by giving up a trick in one suit in exchange for a trick in another.

Dealer West All Vul

K 8 5
8 5 2
A 4
K J 7 3 2
9
A Q 10 9 4
K Q J 8 5
8 4
10 7 3
J 3
10 7 6 3 2
Q 10 5
A Q J 6 4 2
K 7 6
9
A 9 6
West North East South
1 Pass Pass 1
2 3 Pass 4
Pass Pass Pass

Opening Lead K

West leadsK and it is not difficult to see that South is threatened with the loss of a club and three heart tricks. He would like to be able to establish club winners without letting East in to play a heart through the King.

This is neatly accomplished by playing a low diamond for dummy on the first trick. Say that two high tumps from hand, then Ace and King of clubs and a club ruff, he returns to dummy withK and discards two hearts on the established clubs, making an overtirck.