Mastering the Z shot in racquetball will greatly improve your game. It's a difficult shot to learn but with practice and more practice, you'll do it.
Basically, the Z shot is like a Z from any where in the court. But, it is best done while you stand off center.
You hit the front wall as high as possible, then the ball hits the side wall and opposite wall (all without touching the ceiling, floor or back wall -- if the ball touches the ceiling it is not a Z shot) and rebounds parallel to the backwall.
After you try this a couple of times or more, you will notice a spin generates from the 3 walls, and the ball is hard to predict because the direction of the ball reverses.
To hit the Z shot correctly, the ball ends up rolling along the back wall and is impossible to return.
To hit the ball incorrectly the ball will be a very easy set up for the opponent.