This deal occurred in the 2009 Las Vegas Regional:

Vul: None Dir:South	8 6 K J 5 4 3 A 10 8 5 4 3
J 9 3 8 2 J 9 8 3 2 K Q 9		10 7 5 2 A Q 9 6 10 6 5 J 6
	A K Q 4 10 7 K Q 4 3 A 7 2

West	North	East	South
Berkowitz		Cohen	Sontag
--	--	--	1
Pass	1	Pass	2NT
Pass	3	Pass	3
Pass	3NT	(All Pass)

I've simplified the bidding to show a normal "Checkback" auction.

Berkowitz (West) chose to lead the 8.

Would you rather play or defend?

I'll tell it as a story and see if you can spot any errors.

After the heart lead, dummy played low and I won the Q. I returned a diamond and it looks as if declarer has only 7 top tricks.

In dummy, declarer led the 8 and passed it to West's 9. Berkowitz returned the K won by declarer, who exited with the 10.

I won the A and exited with the 7 in this position:

Vul: None Dir:South	8 6 K J 5 -- 10 5 4
J 9 3 -- J 9 8 3 Q		10 7 5 29 6 10 5 --
	A K Q 4 -- K Q 3 7

Sontag won the A and cashed the K and Q. Then, in desperation, he cashed the top spades and threw me in with the 4th round of spades. Lo and behold, I had to give dummy the last two tricks in hearts for the contract.

So, can 3NT always be made after West's heart lead?

Astute readers will notice my error (thanks a lot). I did well to exit with the 7 in the diagrammed position. Exiting with the 2 would have been fatal. In fact, the 2 was the most important card remaining in my hand. I should have played all my high spades under declarer's A-K-Q. Then, when he tried to throw me in with the fourth spade, declarer would have found himself winning the 4 (with me following with the carefully-preserved deuce). That would be a good trade for me. I'd have given him an extra spade, yes, but only for his 8th trick. Then, he would have to give the last 2 tricks to West--down one.

But, I wasn't the only one who took his eye off the ball. At trick 3, when declarer passed a club to David, recall that he continued clubs. Declarer won his A and made a big error. He played his 10 to my ace. WRONG!  He should have cashed his A-K-Q of spades and K-Q of diamonds first. Then, and only then, he should exit in hearts. Now, I have no answer. If I've unblocked all my high spades, declarer would have cashed the 4 before throwing me in with hearts. If I've kept a higher spade, all I get is that high spade and the A. Try it yourself.

Lastly, Berkowitz (West) was also to blame. When he won the 9 at trick three, he should have played a heart. That would have gotten the A out of my hand at the right time. Then, I could never get thrown in during the endgame.

I realize this is a hard deal to follow (thus the "Advanced" tag). Anyone with double-dummy software or the patience to lay out the cards might be able to see all the variations. Bottom line: three errors were made -- one by each expert. I hope that makes all my readers feel better.