Backspin is the ball's rotation around a horizontal axis perpendicular to flight, the spin component that generates lift, shapes trajectory height, and determines how hard a shot stops on landing. Tour pros average around 2,500 rpm of backspin with a driver at roughly 113 mph clubhead speed, producing a flat, penetrating flight; a full sand wedge can spin north of 9,000 rpm, which is why a well-struck wedge can check up or spin back on a firm green. Too much backspin off the tee balloons the shot and kills distance; too little and the ball won't hold a fairway. Distinct from sidespin, which curves the ball rather than lifting it.