The Dentist Coup by Foxymoron

 Anybody looking at the auction below would think that West showed touching faith in his partner's declarer play, but the truth is that 2NT showed g22-24. When I plugged the East hand in to K-R, it spat out 23.15, so I have to give Vampyr credit for good judgement there. We split the range so that we can distinguish bad hands with 20-22 from those that are worth game!

West decided to look for a 5-3 major-suit fit with 5-card puppet Stayman and East showed a four-card major with 3D. West closed proceedings with 3NT and South led the six of hearts. Stefanie won and played a club to the eight, won by North's ten, and a second heart came back. Now East led the king of clubs and South was caught in a dentist coup. If he ducked, declarer can cash the major suit winners and exit with a third club and South is toast, as he either resurrects dummy or gives declarer TWO diamond tricks. If, in the ending, South leads the jack of diamonds, East ducks! In practice South won the second club and exited with another heart, but this just cost the overtrick as declarer unblocked the spades and enjoyed the winning clubs, for 90% of the matchpoints. Ironically, Phil Mattacks and Ken Rolph would have won if they had just saved the overtrick.

The Dentist Coup featured in several books in the 1970s and is a legal play, unlike the Alcatraz Coup, where declarer retracts his revoke having discovered the location of a key card. One I came across recently is the Superglue Coup, related to me by John Probst, a founder member of the Woodberry Bridge Club and doing pretty well despite a couple of strokes. Declarer is playing an ambitious 7H with QJT98 opposite A7654 in dummy and leads the queen, but the next player follows with both the 3 and the 2 at the same time, as though they are superglued together. Now the declarer, knowing the odds, rises with the ace, but the next player shows out. Charlie the Chimp, of course, has the K32.