Source: ACBL Bulletins
This deal is a curiosity piece. I am showing all four hands at once because there are interesting issues for both sides.
South bid to 6
as shown. One thing worth noting is that when you open 2
, your auction can suffer if the opponents get into the bidding. Do you, for instance, know what a pass by North would mean after 3
? How about a double by North? All good questions.
North’s 3NT bid was a practical attempt to describe what he has. South bid 4 , confident that it was forcing. When North raised to 5 , South bid slam, a risky decision. If North had the 
A or the A, he might have shown it over 4. Because there was a possible spade loser, passing 5 could have been right.
West led the J, won by East. East returned a heart on the slim chance that West could ruff. South won the K. He has 11 easy tricks with slim hopes for another. Do you see where it might come from?
This slam basically requires that West have the A K and the spade stopper. If so, West can be squeezed in spades and clubs. From the auction, West certainly has the spade stopper, but the opening lead says he doesn’t have both top clubs. Wouldn’t you lead a club if you had the ace and king?
South does have a chance, however. After winning the heart lead, South should go to dummy with the J and lead a club. If you were East, would you know to play low? If East goes up with the ace, South will ruff and be able to squeeze West.
How can East tell what to do? The first thing that East should appreciate is that South has the A. There’s no way that South would bid 6 if he had no aces outside of diamonds. Come to think of it, if South has a club, bidding 6 is pretty awful for the reason already noted: namely, South should expect North is missing both the A and the A.
The next thing for East to do is visualize what will happen if he plays the A. That will leave West having to guard spades and clubs, and he can’t do that. He will be squeezed. Note that East did well not to lead the A at trick two. That would have led to the squeeze a little faster.
Postmortem
East didn’t double 6 . He has two aces, but he can be sure that South has a void somewhere. If 6 goes down, East and West will usually get a good result. Doubling seldom gains much. If 6 makes, East-West will usually get an under-average result, If 6 is doubled and it makes, East-West will get a lousy result. Note what West had for his 3 bid. It was an excellent effort to interrupt the North-South bid-ding. Even a 2 bid would have been effective. Taking away a level of bidding from the 2 bidder is always a good goal. The 3 bid takes away two rounds ofbidding. Not small potatoes.