Overhand serves may be played in differents ways, such as the overhand floater serve, the overhand spin serve and the power serve.

上手发球有不同的方法，例如上手飘球、上手旋转球和大力发球等。

youdao

Overhand serves may be played in differents ways, such as the overhand floater serve, the overhand spin serve and the power serve.

上手发球有不同的方法，例如上手飘球、手旋转球和大力发球等。

youdao

Serve mostly to weakness but vary the placement and spin some. A 20% variation is enough to keep opponent guessing.

发球主要发往对手的弱点，但是偶而也要变换落点和旋转，只要有20%的变化就可以让对手难以捉摸。

youdao

At the moment, the racket's technology can identify the type of shot a player hits (forehand, backhand, serve), the kind of spin a player imparts on the ball and the power of a swing.

WSJ: Babolat Microchip Racket: The Racket of the Future