(1) RKCB 1430.
(2) Zero key cards.
West leads the ♥5, East follows with the jack. Plan the play.
This is a “Take All Your Chances” deal. You have two chances to land this slam: (1) ruffing out the ♦K; (2) leading up the ♣K if the ♦K doesn’t ruff out.
Win the ♥K, cash the ♦A, cross to the ♥Q and ruff a diamond. If no king appears, cash the ♠A, ruff a spade, and ruff a second diamond. If no king appears, ruff another high spade and lead up to the ♣K. If West plays the jack after you ruff the first diamond, ruff a spade and lead the ♦Q, hoping to entice East to cover if he has the ♦K. If he plays low, ruff the diamond as you don’t want to give up on West having K–J–x or the ♣A onside. Giving yourself chances in both clubs and diamonds gives you a tad more than a 60% chance of success.
West leads the ♠K, East follows with the 2. Plan the play.
The idea is to avoid the heart finesse, if possible. If the ♦Q drops singleton, doubleton or third (about 36.5%), you won’t need the heart finesse at all. The spade throw-in plus the heart discard on the ♦J will do the trick.
Problems arise when the ♦Q doesn’t fall. Getting a count on the West hand helps, however, and the fewer hearts the better.
Win the ♠A, cash the ♦A K, paying off to a singleton diamond with West As you will see, entry considerations favor not cashing a high club first; however, assume the first time you do lead a trump, both follow. We will consider 3–0 trumps later.
Say no queen falls under the ♦A K. Cross to the ♣J using your 10 and ruff a diamond high. If the queen drops, enter dummy with a trump, pitch a heart on the ♦J and exit a spade. You now have a claim.
If the queen doesn’t drop third and West follows to the third diamond, enter dummy with the ♣9, ruff dummy’s last diamond, giving you a complete count on the layout.
Once you have a complete count, the number of hearts West has is crucial. If West started with three or more hearts, you must find East with the ♥K J and take the deep finesse after drawing trumps and exiting a spade. If West started with fewer than three hearts, draw trumps ending in dummy, lead a heart to the queen, cash the ♥A and exit a spade, forcing a ruff-and-sluff return.
If West shows out on the first club (unlikely), you are still alive if the ♦Q is doubleton or third as the throw-in after drawing trumps and discarding a heart on the ♦J still works. If it doesn’t drop and West has three or more hearts, you know what you need to do.
After you cash the ♦A K, both following low, cross to the ♣J and say East shows out. Ruff a diamond and say West shows out. You have a count on the hand. West started with a 6=2=2=3 pattern. If West follows to the third diamond, he either has a singleton or void heart. Same story: Once West has fewer than three hearts, draw trumps ending in dummy, heart to the queen, ♥A, spade. Voila.