Problem

The Auction:

The ♣9 is led against your 3NT contract, East's Ace winning the trick. A heart is switched at trick 2, West wins the Ace and plays back a heart. What do you discard from dummy?

Solution

You have 3 top tricks in diamonds, 2 in clubs since the Ace is dislodged, 1 trick in hearts, and require 3 more tricks. If diamonds lie favorably, you have 2 more tricks there and need just 1 trick in spades. However, if East has four or more diamonds to the Jack, you need 3 spade tricks. If you carelessly discard a spade at trick 3, the contract can no longer be made. It is silly to discard a diamond; when diamonds are favorable, as a trick is wasted unnecessarily. The correct discard is a club, retaining your options in both diamonds and spades. After winning East's ♥10 with the King, you can test diamonds by cashing the King and Queen. When West discards, you can change tack and play on spades. Since West has the ♠A, you can develop 3 spade tricks and land the game.

Congratulations if you came up with the right solution. When this deal was played at a pair event, many declarers failed to make the contract when they discarded a spade from dummy rather than a club.

Par Contract Analysis

The par contract on this deal is 3♠ by North-South