(1) Protecting the minor-suit kings. Sometimes it’s better that the partner of the 1NT bidder declare.
West leads the ♥K. West has two spades, East one. Plan the play.
Start by playing four rounds of clubs ending in dummy and watch the discards. For example, someone with five hearts might discard two hearts.
At IMP scoring, the best play for 10 tricks is to win the ♥A, draw trumps, cash the ♦K and the ♦A and exit a heart.
Unless West has specifically three low diamonds and the ♣A, you are home. If West doesn’t that have that one killer holding, where he can exit a diamond and then take two club tricks after East shifts to a club, what can he do when on lead? If he has the ♦Q, he can cash it or shift to a club, but your ♣K is now your 10th trick. If he shifts to a heart, ruff in dummy, discard a diamond, and ruff a diamond. If diamonds are 4–2, you still have two club losers; if 3–3, you make an overtrick. Your big gain comes when West has a low doubleton diamond. Now West must either lead a club (and the ♣K is your 10th trick) or give you a heart ruff-sluff that is no better for the defense.
At matchpoints, you’d have to decide on how greedy you want to be. Taking the diamond finesse could land you as many as two overtricks if West has ♦Q x x and East the ♣A, but costs you a vulnerable game when East has the ♦Q x x (x) and West the ♣A.
Do you like your hand? You wind up in 7♥ against silent opponents, and the lead is the ♣Q, East encouraging. Plan the play.
The best play to cater to 4–1 spades (no singleton queen) or 4–1 hearts is to win the ♣A, cross to the ♠A and ruff a spade low. If both follow, life is wonderful. Cash the ♥Q J and even if they are 4–1, no problem. Return to your hand via the ♦A, draw trumps and claim.
What if spades are 4–1? Why did I know you would ask that question? If West has the four spades, you are a goner. East will overruff dummy, but that will be the defenders’ last trick, as you still have the wherewithal to ruff a spade and draw trumps.
It is when East has four spades and West a singleton that you have to be careful. On the second spade, West can uppercut dummy, leaving dummy with ♥Q x. If West started with two hearts, you must cash the ♥Q before ruffing a second spade. If you don’t, West will uppercut the dummy again, and East will wind up with a trump trick. If, however, West has three hearts and you cash the ♥Q before ruffing a spade, West will gleefully ruff your third spade, the setting trick.
As it is more likely that West has three hearts than two, after overruffing, return to your hand via the ♦A and lead a third spade. The best West can do is uppercut dummy again, but then you can draw the remaining trumps with the trump ace-king.
If West started with four hearts and one spade, West simply discards on the spades and lets you ruff the second spade with an honor, promoting the fourth trump to the setting trick. Realistically, you can handle 4–1 hearts only when spades are 3–2 (or 4–1 when West has one spade and three hearts).