CONTRACT: 4 South
OPENING LEAD: K (from A-K or K-Q)
Four possible losers: one spade, one heart, one diamond and one club.
Line of play: establish a club trick in dummy (given the favorable lead) and take the finesse in trumps.
Trick 1 W: K, 7, 6, A
Trick 2 S: 5, Q, 9, 8
Trick 3 W: 2, J, 10, 3
Trick 4 N: J, 5, 2, Q
Declarer can win any return from West, pull the remaining trumps and concede the spade ace.
An alternative play for declarer would have been to lead his spade jack at trick two, aiming to establish the king in dummy for a diamond discard.
Declarer makes his contract.
The defense takes three tricks: the heart queen, the spade ace and the club queen.