An endplay (also throw-in), in bridge, is a tactical play where a defender is put on lead at a strategic moment, and then has to make a play that loses one or more tricks.
West led the queen of hearts. Declarer played low from dummy and East took the trick with his singleton ace, and then had to find the entry to West’s hand to acquire his ruff.
The most familiar type of elimination play is the "ruff and discard elimination". The defender who is thrown on lead has the choice between playing on a suit, to your advantage, or giving you a ruff and discard.
This deal gets my vote for the best defense ever. It occurred during the 1985 International Team Trial to pick the U.S. team for that year's Bermuda Bowl world championship. Try it for yourself first.
When you have some kind of a finesse to take to make your contract, put off the finesse until the last possible moment. In the meantime, try to get an accurate count on the opponents' hands.
One of the beauties of bridge is that it gives practitioners a chance to reason and infer, rather than project from a position where everything is known, as in chess.
