West   North   East   South
                                 1NT
pass     2♣      dbl*    2♦
pass    3NT     all pass

* Lead Directing - shows a strong club suit and demands a club lead.

You hold the South hand on this deal, which took place in a team-of-four event. The scoring is IMPs, where the objective is to make your contract and overtricks are insignificant. You open a 15-17 1NT, and end up in 3NT after East doubles partner's 2♣ Stayman bid to request a club lead.

West dutifully leads the ♣9, East overtakes this with the 10. From the lead directing double and West's opening lead, you know that East has the missing club honors. So you duck this trick, in an attempt to sever defensive communications. This maneuver succeeds, as East cashes the ♣A with West following with the ♣4, and then plays the ♣Q to trick 3, with West discarding the ♠10. How do you continue?

Solution:
You have 2 top spade tricks, 2 top heart tricks, 1 club trick, and therefore need 4 tricks from the diamond suit. This seems easy enough. East is the danger hand as he has club winners to run, and it is apparent that you cannot let East on lead. The obvious way to play the diamond suit is to play a diamond to the Ace, and play a diamond back to the Jack, since you're okay even if West wins the trick.

There is a problem with playing a diamond to the Ace - if diamonds split 5-0 with West holding five diamonds, as on this hand, you can score only 2 more diamond tricks, as West will hold Q9xx over your KJ10x. The correct way to tackle the diamond suit is to cross to dummy in one of the major suits, and lead a low diamond from dummy, planning to insert the ten. When East shows out on this deal, you are now prepared to handle the 5-0 break, and insert the ten (playing the King and planning to play a diamond to the 8 works as well). West is welcome to win the Queen, but you will win West's major suit return in hand, play a diamond to the 8, cash the ♦A, come back to hand with the other major suit honor, and enjoy two more diamond tricks.

While the diamond suit combination is not a difficult one, it is easy to be lulled into making the obvious play of diamond to the Ace. This deal is another illustration of the dangers of playing too fast, which is one of the main reasons even expert declarers go down on makeable contracts.

Analysis:
Bridge Baron's double dummy solver confirms that ducking the club at trick one is a necessary play. East can actually make life difficult for declarer by switching to a spade at trick 2. The defense now threatens to take 5 tricks in the form of 2 spades, 2 clubs and 1 diamond. The double dummy solver points out that the contract can always be made. Declarer can overcome this defense playing double dummy in at least a couple of different ways:

Line 1
Declarer can win the spade return in hand with the Ace, and play the ♦J, covered by the Queen and Ace. The ♦8 is now run to West's 9, who returns a spade. Declarer ducks this, to cut communications and put West out of the picture. It is now a simple matter to knock out East's ♣A for the 9th trick.

Line 2
There is another elegant route to 9 tricks. Declarer ducks East's spade switch at trick 2 completely. Declarer wins the spade return with the Ace, and plays the ♦J, covered by the Queen and Ace. Declarer now plays a club towards the King. Say East goes up with the Ace and returns a spade. Declarer wins the King, cashes the Ace and King of hearts, and exits a spade to endplay West, who has to play into declarer's diamond tenace!

There are other variations to the play, you can explore them for yourself using Bridge Baron's double dummy solver.
Par Contract Analysis:
The par contract on this deal is 3NT by North-South.

Bridge Baron deal No : N4145-91436-65018-76104-02618-46632