West   North   East   South
                                 1NT
pass     2♣*    pass    2♦
pass    6NT     all pass

Playing in a pair event where the scoring is matchpoints, you open a 15-17 1NT with the South hand, and soon find yourself in 6NT. West leads the ♠Q, you observe that the diamond suit is the key to the hand. Three tricks in the suit will see you through. You win the first trick in dummy, and noting possible transportation issues later in the hand, decide to tackle the diamond suit immediately, leading a low diamond off of dummy. To your surprise, before the diamond has even made it to your King, East has already played the Queen. What are your thoughts?

Solution:
It is heartening to see East play the ♦Q, as West appears to have the diamond length. According to the Principle of Restricted Choice, East is more likely to have the singleton ♦Q than the QJ doubleton (see the July 7th 2006 Deal of the Week for more on the Principle of Restricted Choice). So should you continue by playing a diamond to the Ten?

If you think about the situation, there is no immediate rush to play a diamond to the Ten. You can give yourself a chance to take all 13 tricks by playing a diamond to the Ace. On this deal, East follows with the ♦J, and you quickly chalk up 13 tricks. What if East did indeed have a singleton ♦Q, and discards on the ♦A? You will come to hand and execute your original plan by leading a diamond to the Ten! The entry situation however is slightly precarious, and you will have to be careful. After East shows out on the ♦A, you cash the King and Queen of clubs, come to hand with the ♥A and lead a diamond to the Ten. Later, the ♠A will provide an entry to the ♣A.

It was important to win the first trick with the ♠K in dummy. If you won the first trick in hand, you will not be able to untangle the entry position, and cannot afford the luxury of playing a diamond to the Ace.

Analysis:
Bridge Baron's double dummy solver agrees that as long as the first trick is won in dummy, South can afford to try for a thirteenth trick by playing a diamond to the Ace.
Par Contract Analysis:
The par contract on this deal is 7NT by North-South.

Bridge Baron deal No : N1007-08495-50313-37421-47531-06853