This deal is from a Swiss Team match at the 2013 Orlando Regional.

Vulnerable against not, South held: AQ976
AK63
84
K4.

His LHO opened 1, which was followed by a 2 overcall. After RHO's pass, South bid 2. It is important to know if your partnership plays this call as forcing (if not, South would have to find a different call). I prefer new suits to be forcing after a 2-level overcall. After 2, South's partner jumped to 4! What's this? It must be a splinter bid, showing spade support and short hearts. South now used RKC and upon learning that only 1 keycard was missing, he bid 6.

K43 2 AKQ1073 876

AQ976 AK63 84 K4

West led the Q.Surely, from West's opening bid, the A is wrong. Declarer has to focus on both the spades and diamonds. If both suits are 3-2, there are 13 easy tricks. The next logical thought should be, "What if both suits are not 3-2?"

If diamonds are 4-1, the suit can be set up by ruffing one, but that would then require an entry (so, spades would need to be 3-2 and would have to be drawn ending in dummy).

If spades are 4-1, the suit can be picked up in some situations. For example, if West was dealt a singleton jack or ten, declarer could lay down the ace, then cross to the king and take a marked finesse to the 9.

With all that in mind, what is the best way to play this slam?

The winning play is to try to combine as many chances as possible. Win the A and lay down the A. Assume nothing interesting happens (no jack or ten). Continue with the Q. If one player has J10xx, you are probably down. But, everyone follows, so you are alive. What next?

If diamonds are also 3-2, you will soon claim, so you have to again ask, "what if diamonds are 4-1?"  The answer is that if the player with one diamond happens to have only 2 spades, you can still make the contract. Don't draw the last trump yet. Play two top diamonds. If everyone follows, play the K and claim. If the suit is 4-1 (and you are lucky enough that nobody could ruff in), you can now trump a small diamond in hand (to set up the suit) and then cross to the K to run the diamonds and make 12 tricks (5 spades, 5 diamonds and the AK).

This was the Real Deal from Orlando:

Vul: North-South Dir:West	K43 2 AKQ1073 876
J8 QJ10975 2 AQJ9		1052 84 J965 10532
	AQ976 AK63 84 K4

After laying down the top two spades, declarer played as suggested to make his contract. The full deal shows that West could have made a spectacular falsecard. On declarer's A,  what if West were to throw the J (which couldn't hurt). Now, declarer might take the bait and play for 4-1 spades. If he next crossed to the K, he would no longer be able to make the contract. Try it!