Solution:
You finish drawing trumps, pitching two hearts from dummy, while being careful to keep a spade in case it is necessary for a squeeze. You have only nine tricks on top - 5 diamonds, 2 hearts and 2 clubs. You need the club finesse to work, for starters. In addition, you need some sort of squeeze for your game-going trick. Let us start out by counting East's distribution - he has 7 spades and 1 diamond, and he either has 3 hearts and 2 clubs or 2 hearts and 3 clubs. In the former case, i.e. when East has 3 hearts and 2 clubs, he can be squeezed in spades and hearts. In the latter case, since West is the defender with heart length, the winning play would be to squeeze him in clubs and hearts.

The key is to discover more about East's distribution, so that you know which of the above two lines you should adopt. After drawing trumps, you should play ♣A, a club to the jack, and cash the ♣K. If East follows to this trick, you know that he is 7-2-1-3, and you therefore should plan to squeeze West. You will return to hand by ruffing a spade, squeezing West in the process. Instead, if East discards a spade on the third club, you will ruff a club back to hand, squeezing East in spades and hearts.

To render the analysis complete, note that the case where East's distribution is 7-4-1-1 or 7-5-0-0 should be treated in a similar fashion to the case where East's distribution is 7-3-1-2. Finally, when East is 7-1-1-4 or 7-0-1-5, the contract cannot be made, as East will discard after dummy.

Analysis:
Bridge Baron's double dummy solver points out that the contract can be defeated if West leads a heart, or finds a heart shift when he gets in with the ♦A. West would then lead a second heart when he gets in with the ♦Q, killing the entries required for a squeeze.

Bridge Baron's Line of Play
Bridge Baron did not get it entirely right, and achieved half credit. Bridge Baron played to squeeze East in spades and hearts, which worked as the cards were; this line of play would have failed if West held the heart length.
Par Contract Analysis:
The par contract on this deal is 4♦ by North-South.

Bridge Baron deal No : N0542-01488-93342-29809-39010-40976