 Federer plays with a single @-@ handed backhand , which gives him great variety . He employs the slice , occasionally using it to lure his opponent to the net and deliver a passing shot . Federer can also fire <unk> winners and possesses a ' flick ' backhand with which he can generate pace with his wrist ; this is usually used to pass the opponent at the net . His serve is difficult to read because he always uses a similar ball toss , regardless of what type of serve he is going to hit and where he aims to hit it , and turns his back to his opponents during his motion . He is often able to produce big serves on key points during a match . His first serve is typically around 200 km / h ( 125 mph ) ; however , he is capable of serving at 220 km / h ( 137 mph ) . Federer is also accomplished at serve and <unk> , and employed this tactic frequently in his early career . 
