This deal is courtesy of Eugene Hung, who not only does a great job editing my bridge software, but also has an eye for "Real Deals." This comes from the 2010 Grand National Teams where South held:

 
K 9
A K 8 3
Q J 6 3
A K 4
He opened 2NT and his partner bid 3. Over his 3, partner bid 3. What's that?

If partner had 5 spades, he would have used a Jacoby Transfer. If he had 4 spades, he would have bid 3NT next (and you would know he had 4 since he bothered to use Stayman).

Accordingly, the Standard treatment for bidding the other major (also this would apply to 2NT-3-3-4) is to use it as an artificial bid. What does it mean? The responder has 4-card support and slam interest.

So, partner has 4 hearts with you and interest in slam. Should you cooperate? Your range was 20-21, so you are "minimum," but I think you should cooperate. It is a decent 20 and the most important consideration for cooperating in a slam investigation is trump quality. If South's hearts were, say, K832, he should sign-off in 4. Here, he can control-bid 4. After this, partner uses RKC to land South in 6.

Vul: Dlr:	A Q J 2 J 6 5 4 A 2 Q 3 2
	K 9 A K 8 3 Q J 6 3 A K 4

How should you play with the 10 opening lead? 

The heart suit is complex. You could cover with the jack and then if the queen is played, try to drop (or finesse for) the 9. You could play low from dummy and hope East has Qx or a singleton Q. How should you play the heart suit?

This is one of my trick questions. From the lead, you assume East has the heart queen (who would lead from the trump queen against a slam?). On the assumption that a singleton trump is not a likely lead, you can guarantee your contract. As long as East started with Q or Qx or Qxx, you are cold. It doesn't matter if the K is onside.

Play low from dummy (you don't want to waste the J if the Queen is singleton or doubleton) and win your A. Then lay down the K (praying that West doesn't show out). When everyone follows, you can claim. If the Q falls, you will draw the other trump and be on the diamond finesse for an overtrick. Let's look at the Real Deal:

Vul: N-S Dlr: South	A Q J 2 J 6 5 4 A 2 Q 3 2
10 8 7 4  10 9 8 5 4 J 8 7 6		6 5 3 Q 7 2 K 10 9 7 10 9 5
	K 9 A K 8 3 Q J 6 3 A K 4

As you can see, the Q doesn't fall, but that is no problem. Surely, you won't take that losing diamond finesse, will you?

After the top two trumps, just strip the hand. Cash the top clubs, then the top spades (throwing diamonds). Now, exit in hearts and East must lead from his K (or, if he had any black cards left, he can also give a ruff-sluff).

So, is this plan fool-proof (once East has Qxx)?  No.

The fly in the ointment is that East doesn't have to cooperate by following to all those black winners. On this deal, he does (by the time the 4th spade comes, it won't do him any good to ruff in). However, if he had a doubleton in one of the black suits, you might be defeated if East gets to ruff in early in the black suit you play and exit in the other black suit. Then, you would be at the mercy of the diamond finesse.