Man With No Name: The way I figure, there's really not too much future with a sawed-off runt like you.
Tuco: I'll kill you.
Man With No Name: If you do that... You'll always be poor... Just like the greasy rat you are.
Tuco: There are two kinds of spurs, my friend. Those that come in by the door; those that come in by the window.
Man With No Name: Every gun makes its own tune.
Tuco: You became a priest because you were too much of a coward to do what I do.
Tuco: Hurrah! Hurrah for the Confederacy! HURRAH! Down with General Grant! Hurrah for General... What's his name? Lee! LEE! Ha ha. God is with us because he hates the Yanks too. HURRAH!
Man With No Name: God is not on our side because he hates idiots also.
Chosen answer: Tuco knew he had a better chance at survival (and the gold) by playing along with Blondie and keeping his balance on the cross, hoping Blondie does not miss the rope when he shoots. This final, deadly game was preferable to being shot outright by Blondie and dying a poor man.
Scott215
Tuco had no idea that Blondie's intention was to shoot the rope and let him live.