structural:expansion
Backspin

Backspin is where the bottom half of the ball is rotating away from the player, and is imparted by striking the base of the ball with a downward movement. At the professional level, backspin is usually used defensively in order to keep the ball low. Backspin is commonly employed in service because it is harder to produce an offensive return, though at the professional level most people serve sidespin with either backspin or topspin. Due to the initial lift of the ball, there is a limit on how much speed with which one can hit the ball without missing the opponent's side of the table. However, backspin also makes it harder for the opponent to return the ball with great speed because of the required angular precision of the return. Alterations are frequently made to regulations regarding equipment in an effort to maintain a balance between defensive and offensive spin choices. It is actually possible to smash with backspin offensively, but only on high balls that are close to the net.