Great servers have realized that power and pace are not the end-all and be-all, and that their killer shots must be backed up with a solid return game.

Serena Williams may have the best return of serve in tennis history ... The key to the shot is how it starts: with her stance. Williams prepares to return by turning not only her shoulders ...

China's Peng Shuai serves to Japan's Nao Hibino during their first round singles match at the Australian Open tennis championship in Melbourne, Australia, in January 2020. (AP file photo) ...