The Squeeze-Trim-Endplay: Hand
This is from "Inspired Cardplay", by Bird and Hoffman.
You are in 6 spades. Lefty has overcalled an unusual no trump (at favorable vulnerability), suggesting at least 5-5 in the minors. The opening lead is the 2 of hearts.
You have many choices for how to play this hand. The heart lead, an obvious singleton, allows you to pitch your diamond losers. You have to do this after drawing at least two rounds of trump. (As it turns out, most of the ways of actually making this hand require a 3-2 trump break.)
You then have 10 winners, 11 after the queen of clubs is knocked out. You have a club threat in your fifth club, and you have an endplay situation in clubs.
You can lead towards the jack of clubs. Lefty probably has the queen and probably will play it. That gives you 4 clubs and the contract, so that's a good way to play the hand. But what if Lefty doesn't play the queen?
Now you have a much better endplay situation in clubs. If Lefty has AQJ of diamonds, then you can endplay lefty in diamonds to lead away from Q9x of clubs, given you your fourth club trick. However, Righty could easily have a diamond honor. So the play that gives you problems is if Lefty ducks.
Okay, let's say you do this club play and Lefty ducks. What now? If you could run your hearts and spades, you could come down to just AK108 of clubs in your hand. If Lefty saves Q9xx, lefty can be endplayed in clubs.
However, once you play your last trump, Lefty is relieved of this obligation to save a long club. So Lefty can come down to Qxx of clubs and the A of diamonds, or Qxx of clubs and a small diamond (assuming Righty has a diamond honor).
Okay, let's back up a trick. Suppose you come down to a trump and the AK108 of clubs. Lefty has to save 4 clubs -- it is not yet safe to through a small club -- and a diamond. If you could force Lefty to play a diamond on your last trump, you would have your endplay.
Fortunately, you can force Lefty to play a diamond -- if you lead a diamond from the dummy and trump it!
This of course is the squeeze-trim-endplay. How could you recognize it? The throw-in/endplay suit is clubs. You want to throw Lefty in in clubs, to get 4-tricks. As will usually be the case, Lefty cannot pitch a card in clubs until you release your control in the exit suit. The exit suit is diamonds, and you have a first-round control.
Finally, your loser count is two. This is a little more obvious once you have one your jack of clubs.
One of the tricky parts of the hand is that after playing your last free winner, you have to be in dummy so that you can lead a diamond. The only way to get to dummy is by leading a third round of trumps. That means you have to ruff one of dummy's red cards. Fortunately, that isn't hard. For example, you could draw two rounds of trumps, ending in dummy, pitch your diamonds on the hearts, and ruff a red card, say another heart. In this position, a trump to dummy squeezes Lefty.
You can't play clubs before doing that, because then Lefty can win the queen and give Righty a club ruff. Fortunately, the endplay still works. If Lefty pitches a diamond, you simply lead clubs and set up your long club, with the trump as a control. If Lefty plays a diamond, you trim the last diamond from Lefty's hand, then lead towards the jack of clubs. If Lefty plays low, a club to the 10 (or 8) endplays lefty. If Lefty plays the queen of clubs when you lead towards the board, you have to remember to unblock the jack.
Squeeze-Trim-Endplay: Trump as a Control