In bridge there are many types of coups, some of which involve far-sighted unblocking, entry promoting, plays. One of the more spectular ones goes under the name of The Pitts Coup. It occurs by ruffing with a card higher than necessary as a sacrifice or unblocking play. In this example it allows declarer to lead through one opponent at the table. Having come down to a five card ending declarer ( South ) needs to take all the remaing tricks to steer the 4S contract home.
North : Ax....xxx.....none...none
East : Qx... xx......K........none
South : KJ...none....xxx....none
West : x.....Q98....A........none
So South by leading a small diamond crashes the A/K of diamonds, but it is essential that he ruffs the trick with the Ace. Then he finesses East's queen of spades on the way back into his K-J, and with two established diamonds to cash at the finish the coup has been successfully completed.
However, a much better example of the Pitts Coup can be seen in the following hand :
West : x.......Ax....xxxx.....KJxxxx
East : AQJ9x..J97...xx......xxx
( Dummy comes down with xxx....K106...KQJxx.....AQ )
Defending a 4H contract, West leads his singleton spade to partner's known suit. East takes the trick with his Ace, and promptly returns the queen, covered by declarer's king, which of course sets up a winning spade trick in East's hand. But the problem is how to get East back in to take the trick ?
Answer: The Pitts Coup. Ruff the trick with the Ace of trumps ! And then exit with either a club or a diamond. Now partner will get in with a heart ( no matter how declarer tackles the suit ) to enjoy his spade winner and defeat the contract.
If, as many impulsive defenders might do, West ruffs the spade with a low trump, and exits in the same way, declarer is home and dry. Once South gets in, the play of a low heart immediately brings out the Ace. This now allows declarer to pick up partner's J9 wihout any difficulty......and his losing spades disappear under a deluge of diamonds and clubs.