Test your play #1

This deal is from the U.S. Team Trials in 1969. Let's see how you would fare.

                ♠ 7 6 5
                ♥ 7 6
                ♦ 10 9 8 7 6 5
                ♣ A 2
==
                ♠ A K 3
                ♥ A K
                ♦ Q 3 2
                ♣ K J 5 4 3

You open 2NT and partner raises to 3NT. West leads the ♠Q and East unblocks the 10. Do you win it or duck?

If you duck, West can shift to a heart and attack that suit. Alternatively, West can shift to a club and attack your entry to dummy's diamonds.

Let's say you win and lead the ♦Q, hoping for something good. West wins the ♦A, East plays the 4. West now leads the ♠J as East plays the deuce.

Do you win it or duck? Here are all four hands:

                ♠ 7 6 5
                ♥ 7 6
                ♦ 10 9 8 7 6 5
                ♣ A 2
♠ Q J 9 8 4                    ♠ 10 2
♥ 9 8 5                        ♥ Q J 10 4 3 2
♦ A J                          ♦ K 4
♣ Q 10 9                       ♣ 8 7 6
                ♠ A K 3
                ♥ A K
                ♦ Q 3 2
                ♣ K J 5 4 3

If you duck, West will continue and East can make the brilliant discard of the ♦K, creating an entry to the West hand.

Do you notice anything? West must let East win the first diamond with the king and return his ♠2 to ensure the set.

Back to trick one: If declarer ducks the spade, wins the continuation and plays the ♦Q, West can win the ace while East discards the king! (East can also discard the ♦K on the third round of spades, but that's not as spectacular.)