A back screen is set behind a defender, on the blind side he is not watching. His man cuts to the rim off it while his head is still turned toward the ball. The screener sets his feet, stays still, and lets the cutter run his own defender into him.
Why coaches use it
Every off-ball defender is taught to see his man and the ball at the same time, which means he stands half turned away from the basket. A back screen attacks that stance directly. He does not see it coming, and by the time he feels it the cutter is already past him.
It does work even when nobody scores. A back screen drags a help defender down toward the baseline, and help stuck low cannot get back out to the perimeter. That is the point of the UCLA cut, and of Chin, where a back screen and a flare happen on the same count so the defense has to lose one of them.
The most common version in the pro game is on the ball screen: a shooter back-screens the roller’s defender. That is Spain pick-and-roll — same principle, different victim.
How it is guarded
Three honest answers, each with a price.
- Switch. Clean and simple, and it is why so many back screens are set by a big for a guard: the switch hands you a size mismatch to seal.
- Talk and jump to the ball. The screener’s defender calls it early and the cutter’s defender steps to the ball side of the screen, so the cut goes away from the rim instead of straight down it.
- Bump the cutter. The screener’s defender steps into the cutter for a beat and recovers, the same idea as tagging a roller. It costs you a moment of contact with the shooter you left.
Watch for the back screen that is really a flare. If the cutter comes off it going away from the basket, the defender’s instinct to jump toward the rim is exactly wrong.