How far from the back glass to stand
When defending, stand a couple of metres in front of the back glass rather than against it. That leaves room for the ball to come off the glass and for you to turn with it.
Trin 1
Standing with your back to the glass: the ball bounces and hits the glass behind you, and you are jammed.
Trin 2
A couple of metres off the glass, you can move back with the ball and let it come off the glass to you.
Trin 3
You play it back with a lob, or low cross-court, and come forward again.