Surprise!

This hand, I believe, lends itself productively to a count of winners, particularly in view of the absence of any real ambiguity, and perhaps not least, in view of the results. Of those who played the hand in hearts, fewer than half picked up the easy 12 tricks that are there for the taking, some not even picking up eleven, and only one picked up 13, which is the surprise I'm going to get to at the end.
A Q 7 5
K Q 7 3
K 6 3 2
3
8 2 J 10 9 6 4
10 8 4 5 2
Q J 10 9 5 4 8
6 5 K Q J 8 2
K 3
A J 9 6
A 7 Contract: 6 hearts
A 10 9 7 4 Opening lead: spade or diamond

Well, let's start counting our top winners: we have 3 spades, 2 diamonds and a top club for six. No finesses, no need for even breaks here. Now if we have six side-suit winners, then we're going to want six heart winners to bring us up to twelve. (Not everybody bid slam, but even those who didn't traditionally like to pick up overtricks.) And the path to six heart winners is pretty clear: we'll ruff two clubs, no?
On an opening spade lead, let it ride to the K. Cash the ace of clubs and ruff a club, get back with a diamond, ruff a club high, cash your remaining heart honor, and come to the A J with the remaining trump in dummy. Yes, we needed a 3-2 heart break, but it was there, and there's nothing unusual about that. And here's the surprise.
On a diamond opening lead, the line is substantially the same, only you'll get back with a low spade after the first club ruff.
When you get done drawing trump, go to the king of diamonds (if it wasn't used on opening lead) and ruff a diamond coming back and you'll find you've squeezed East! If you're looking at the A of diamonds and a trump, cash 'em both. The hand will then look like this (with East yet to play):

A Q 7
------
------
------
------ J 10 9
------ ------
Q J 10 ------
------ K
3
------
------
10 9
If East doesn't look squeezed here, it's because he hasn't played yet to trick 10. Obviously he cannot hold the top club and 3 spades at the end of the trick. It's a bonus. If you play the hand right for twelve tricks, you are handed a baker's dozen, provided you use up that last trump! (which not many did).