Source: 2014 Canberra the Summer Festival, Bulletin 2
While the bidding was a little forward, there is nothing wrong with the final contract. How do you plan to make twelve tricks after West leads the jack of diamonds?
Solution:
Suppose the full deal is something like this:
If you win the first trick with the king of diamonds in hand then it will no longer be possible to make the contract! After cashing the queen and jack of spades in dummy and ruffing a heart ruff you won’t have an entry back to hand to draw the remaining trumps.
If you try to cash the ace and queen of diamonds then, after East ruffs in on the third round of the suit, you will be left with two club losers.
The proper course is to win the diamond lead in dummy with the ace (say), cash the queen and jack of trumps and then organise a heart ruff. After returning to your hand with the king of diamonds, you will draw East’s two remaining trumps with the ace and king. All that left to do then is to cross to dummy with the ace of clubs and discard one of your losing clubs on queen of diamonds. You will make five trumps, two hearts, a heart ruff, three diamonds and a club for a total of twelve tricks.