Problem

The Auction:

After an uneventful auction South declares 3NT.

West leads the ♦3. The declarer plays a small diamond from dummy, East plays the ♦10 and South takes the first trick with the ♦Q.

We ask you to take the seat of South – how are you going to proceed?

Contract: 3NTS

Vulnerable: none

Solution

After the opening lead your diamond suit is left without a stopper. You can count four quick tricks – three in spades plus the ♥A. And if the ♣ K is onside, you can take five tricks in clubs.

To finesse clubs you need of course to cross over to dummy. This seems not to be a problem, as you have two entry points to the dummy – the ♠A and ♠Q. But what if the missing four clubs are split 4-0? Then you would need one more entry point to the dummy’s hand and you must somehow find it.

You cannot hope that the opponents will let dummy’s ♥Q win a trick, as they must certainly be eager to regain the lead and cash in the tricks in diamonds. Thus you must use spades to enter dummy three times (if needed). You hold the ♠Kxx, dummy has the ♠AQ10 and one of the opponents has the ♠J. So while creating the third entry to dummy you must finesse if needed.

The best way out if this corner seems to lead the ♠K and win the first trick in spades with dummy’s ace (trick 2). Next you lead a small club from dummy and play the ♣J – West discards the ♥2, so you were right to be cautious, clubs were split 4-0 (trick 3).

Now you lead a small spade again. West plays the ♠9 and as you know you must get third time to dummy you play the ♠10, which holds (trick 4). Then you lead the ♣8 from dummy, East plays the ♣10, your queen wins that trick as West discards the ♠J (trick 5). You lead your last small spade to dummy’s queen (trick 6) and lead clubs from dummy for the third time. East ducks, so your ♣9 wins the trick (trick 7). Now you can lead the ♣A and take another trick with your ♣5 (tricks 8, 9), then win one more trick with the ♥A (trick 10). The last three tricks belong to the opponents, as they hold the ◆AK and have the ♥K (tricks 11, 12, 13).

With four cards missing the most probable distributions are 3-1 (49.74%) and 2-2 (40.70%). While the 4-0 split has only a 9.57% probability, it can still crop up. The declarer was wise to keep the possibility in mind and thus by playing his king under dummy`s ace kept open a way to get into dummy three times.

The obvious play would have been to lead a small spade to dummy’s ace, finesse clubs. Then repeat – lead a small spade to dummy’s queen, finesse clubs. This way the declarer could not have finessed clubs for the third time and would have lost one trick in clubs and four in diamonds, down one.

Par Contract Analysis

The par contract on this hand is 4NT by North-South.