Last week was one of the local Atlanta sectionals. As often happens in tournaments with many knockouts, there were a couple of teams that repeatedly met all week, usually in the finals.
One of the most interesting play problems from early in the week against this team might have slipped under the radar. Playing IMPs in a cold 4S contract, the best line to make 6 may well have gone unnoticed. However, bidding to 6 is quite reasonable; in fact my counterpart at the other table did just that, down 1.

I can't say what defense happened at the other table, but at my table I received a low diamond lead to the J and A, with a diamond return. At this point it's all about finding the best squeeze.
Commonly when you have Qx opposite the Ace, a Vienna coup style squeeze is called for: win the diamond return (discarding a heart from hand), cash the Ace of clubs, and run the trumps leading to an ending like this:

If the K of clubs is in the same hand as a 5 card heart suit, they will be squeezed. This does however require a 5-2 heart break as well as the K in that hand because of the miserable heart spots. Of course, alternate options exist on the hand. With the Ten of H in hand, it would be nice to keep 3 hearts in hand and use the club threat on the board instead of in hand. The best way to do that is to ruff out the clubs, using both the AC and 7S as entries. Of course, that requires 2-1 trumps. If you discard a club right away and find trumps 3-0, you can no longer fall back on the other heart position.
Because of that, I felt at the table the best line was to ruff the diamond return and test trumps. If trumps are 3-0, go after the first line listed above. If trumps are 2-1, draw trumps, club to the A, ruff a club, trump to the 7, ruff a club, run the trumps to this ending:

Now with the 10H still in play, we can win if the KJ of clubs ruff out tripleton or less, if the long club is with 5 hearts, or if the long club is with both the missing heart honors. This seemed like the best chance at the table, but today it didn't work. Clubs are 4-3, hearts are 3-4, honors are split. At the time I didn't think anything of it, it seemed like making 5 was the limit. I was wrong.
With more time to think about the hand later, I realized that there was a rare squeeze position available called a clash squeeze. In a clash squeeze, one opponent is forced to come down to a singleton (usually an honor) to keep cards in multiple suits, exposing their partner to a finesse that didn't exist before. To make it work, I needed the long club on my left with at least one of the 2 heart honors - as well as 2-1 spades.
Going back to step 1, I needed to discard on the diamond return. Not a heart though as in line #1, but the club - just assume we can ruff out the suit and the 7S will be an entry. So, win the diamond, draw trumps in 2 rounds, club to the A, ruff a club, trump to the 7, ruff a club, run the trumps in this ending:

On the last trump, West obviously cannot discard their club. If they discard their last diamond, then East will be squeezed in the red suits when we discard a club from the board. To protect their partner from that West keeps the QD as well, discarding a low heart. If declarer reads the position right, now a heart to the board (West's honor popping up) and a heart back to the 10 will see the rest of the tricks for making 6.
The full hand: