This Real Deal was played in the 2011 Sarasota, Florida Regional. In a knockout event, South held: 

K J 3
A J 10 8 6 4
A 4 2
4
.

At his favorable vulnerability he dealt and opened 1. Partner responded with 2NT, Jacoby.

South, playing the "basic version" of the convention rebid 3 to indicate shortness. North followed with 3. What's that?

Hearts are surely trump, so theoretically this is a "control-bid." But, on the 3-level (especially below 3 of the trump suit), we don't get crazy about showing controls. I'd think of 3 more as "something in diamonds and I am alive for any slam possibility." Certainly, this should be a fast-arrival auction; if either player at any point bids 4, that is the weakest action. What should you do? In spite of having "only" 13 HCP, you have tons of upgrades. You have prime cards, good trumps and 6 of them! You are surely interested in cooperating. You could bid 3, foreword going, or maybe better is 3 to show something there. Partner bids 4 next. He is still interested and has a club control. You still are too good to sign-off. I like either 4 or maybe even Blackwood. That's enough bidding theory for one deal--let's say you end up in 6 (you will blame partner if you are too high), and you get the Q lead:

 

 

	A 9 5 4 9 7 5 3 K Q 3 A 5
	K J 3 A J 10 8 6 4 A 4 2 4

In spite of only 13 opposite 13 in HCP, this isn't a bad slam. What is your plan?

Your only possible losers are in hearts and spades. If West has the KQ2, you are dead. If East has it, you can pick up the suit. Accordingly, win the first diamond in dummy and advance the 9. You never know when somebody might cover.

 

No luck. East plays a smooth 2.

And you?

The safety play to make sure (100% sure) of only one heart loser is to put in the jack. Even if it loses, you will have the rest of the hearts and be able to rely on the spade finesse. If West shows out, you can pat yourself on the back for your safety.

However, the correct play in the heart suit may not take the entire deal into account.

For the small gain of East having all three hearts, your finesse gives up on the bigger picture. If you play the ace and West follows, you are in great shape. You will have only one heart loser and would also be unlikely to have a spade loser.

After the A wins, you can strip the minors and exit in hearts. If West wins, he is endplayed into a free finesse in spades or giving you a ruff-sluff.  Even if East wins, he will have to break spades and you will succeed if he has either the Q or the 10 or both (you will play low and West will have to play his big one if he has it). If West has both the Q and the 10 and East has 2 hearts, it just isn't your day.

I don't expect anyone to calculate the exact percentages, but surely it is better to play for 2-1 hearts (and almost a sure claim) than to guard against an unlikely 3-0 heart break (and still not even have a claim). 

 

 

Here is the Real Deal:

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

As you can see, after the club lead, declarer would go down if he finesses in hearts. West would safely exit and sit back and wait for his spade trick. However, winning the A and stripping the hand is a successful line of play. When West gets thrown in with the K he has to present South his contract. This deal was pushed at 980 when both South players in the match skillfully bid and made their heart slam.