Backspin and the Float

Backspin — also called slice — is topspin's opposite. The ball's top spins backward, and the Magnus effect pushes upward, partially fighting gravity. The result: a shot that floats, stays low, and skids on the bounce.

Slice serves are devastatingly effective because the ball curves sideways through the air and then skids low off the court surface, pulling the returner wide. Roger Federer's slice backhand exemplifies controlled backspin — the ball barely rises after the bounce, forcing opponents to dig it up from below the net cord. The physics rewards precision over power.