Fuzzy Squeeze Example 1
As you can see, 4 hearts requires either the king of diamonds to be onside or the ace of clubs to be onside. The play is straightforward.
In 3NT, you of course get an opening spade lead. You win with your king (for better or worse) and run the hearts, fuzzy squeezing your opponents in a serious way.
In 4H, you draw trumps then stop playing hearts, retaining your remaining hearts as controls. Whatever you try next, the opps can safely return spades. (In fact, once you try the club finesse, then can safely play clubs.)
In 3NT with a fuzzy squeeze, they don't necessarily have this option. If one player saves spades, that player cannot also save diamonds and clubs. Suppose LHO throws the J8x of diamonds. If you read this as the player saving spades and clubs, you can actually get 3 diamond tricks by double-finessing.
It turns out that RHO has Qx of clubs and can safely pitch them. But he doesn't know that. You could have KJ of clubs and require a guess or be afraid to attack the suit until the queen is pitched.
Or, if either opp abandons either diamonds or clubs, that gives you good information which suit to play and how to play it.
So, as it turns out, you pitch a spade and then the opps work out that they can safely pitch spades. And they do. When you are done running the hearts, you also cash your ace of spades, the opponents both discarding on this.
And, as fate would have it, they see you are pitching clubs, they figure out that you are probably going to attack diamonds next, and everyone comes down to the same distribution: 2 clubs and 3 diamonds. The irony is that in 4H, declarers do not cash all of their hearts precisely because they are afraid when the lose the lead in clubs or diamonds, the opps will run spades. But this does not happen.
Instead, declarer is in the enviable position that if she loses a trick, the opps will have to lead on of the suits she is interested in.
So she played a small diamond to the seven, losing to the eight. LHO now had to break diamonds or clubs. He could have worked out that a diamond return was safe and a club would give up a trick, but he did not. So he led a club away from the ace.
So, in a turn of bad fortune for the 4H bidders, both finesses were offside and they all went down in 4H. Meanwhile, the 3NT contract made 4.
Okay, back to defender on lead after winning his eight of diamonds. There are numerious inferences; I will focus on those relevant to the fuzzy squeeze position. One inference is that declarer cannot have the king of diamonds. The board has the queen of diamonds, and at this stage declarer would play the king to knock out the ace and set up a sure trick for the queen. Declarer has to have some points (on the bidding, at least 6 more) and a reason for attacking diamonds. So declarer needs the ace, but probably lacks either the jack or the 10, or otherwise those would have been played. Similarly, declarer's clubs almost have to be Kx . With the ace, declarer would just play a diamond to the ace and then a diamond towards the queen. With Qx, declarer would make sure to first cash the ace of diamonds. With Kxx, declarer would have Ax of diamonds and hence blocked herself from the queen and removing any endplay possibilities.
There is more. In the traditional squeeze, it is to the defender's benefit to come down to the same number of cards in a suit as declarer/dummy. Because the defenders are hoping to one just one trick, being endplayed doesn't matter.
In the fuzzy squeeze, part of the problem is that it is very advantageous to have more cards in a suit than declarer. It would have been nice if a lot of spades were still out. Then declarer would have had to cash her ace of diamonds first before trying for a tenth trick. A lot of clubs would have worked too.
Here, the situation is even worse. If the defender's pare themselves down to exactly the same distribution as declarer and dummy, they are ensuring that declarer will make as many tricks at no trump as the other declarers made in hearts. It is mandatory for them to try to get one more. That means saving at least one extra spade.
Note also that if they had both saved one spade after the run of the diamonds, declarer could have acheieved the exact same end position by cashing the ace of spades. But declarer could not have afforded to do that. Then when the one defender was possibly endplayed, the defender could have exited with a spade.