Morton's fork coup

Morton's Fork is a coup in contract bridge that forces an opponent to choose between:

1. letting declarer establish extra tricks in the suit led; or
2. losing the opportunity to win any trick in the suit led.

It takes its name from the expression Morton's Fork.^[1]

Example

It appears that South has both a heart and a club loser. Although South can establish another winner in diamonds, just one discard on a diamond honor doesn't help.

South receives the lead of the ♦J against 6♠. However, there are two ways that the contract can be made. South might manage to avoid any heart loser. Or, South might take two heart tricks; in that case, South could discard one club on the ♥K and another club on a diamond honor.

Judging from the opening lead that East holds the ♦A, South plays the ♦9 from dummy at the first trick, ruffs in hand, and draws trumps. Hoping that West holds the ♥A, South leads the ♥7, executing Morton's Fork:

Note that declarer must be careful not to play a high diamond on the opening lead, as East could then withhold the ace. That would force the declarer to choose a discard prematurely. South must get a discard on a diamond honor eventually, but not before West has been forced to decide whether to take the ♥A or duck it. Only then will South know whether to discard a heart or a club on the diamond winner.

Example defense

Robert Gray^[2] gives this spectacular example of an impossible defense to Morton's Fork. West leads the ♣2 against South's six club contract. South wins and initiates the coup by leading the ♠8.

If West takes the ♠A, he might as well continue with the ♣3. South wins and leads a heart, covered and ruffed. A third club to South's hand, and another heart, again covered and ruffed. A diamond to South's hand, and a third heart covered and ruffed. The ♠K is cashed, and then another diamond to South's hand allows dummy's last two losing diamonds to be discarded on the ♠Q and the established heart.

If West ducks the ♠A at the second trick, South sets up a heart via ruffing finesses as before, discarding dummy's losing spade on the established heart. Now a third diamond from South either wins or establishes dummy's ♦10, and South has twelve tricks: one spade, one heart, three diamonds and seven clubs.

Gray points out that to defeat the contract, West must lead the ♥2 at trick one. (He goes on, "And I hope that is not too obvious.") Against the opening lead of the ♥2, South must discard from dummy before West has been forced to play to South's spade lead. If South discards dummy's spade at trick one, West's ♠A will later take dummy's ♠K, and South must lose a spade and a diamond. If South discards a diamond from dummy, West ducks South's spade lead, saving his ♠A for the ♠Q, and again South must lose a spade and a diamond.

Gray speculates on a name for West's opening lead coup: "This play of giving declarer a trick early . . . is probably worth a name. The Anti-Morton Coup or the Down With Morton Coup spring to mind, but these names seem rather unfriendly. Let us settle for the Morton Coup Defense."

See also

• Belladonna coup

References

1. ↑ Frey et al. (1976). The Official Encyclopedia of Bridge, p. 295. ISBN 0-517-52724-3.
2. ↑ Gray, Robert. The Bridge World, March 1973