Originally Posted by S&V Specialist
Flat serve down the T. Stuns them mentally and allows for much easier deuce points. If for some reason my flat serve isn't seeming too reliable then I go with a kick serve to their backhand.
My flat ones tend to be long
I will try on the first serve but I have setup with racket bouncing ball to tossing hand to get the proper rhythm in my set up
The kick ones are more reliable as if I can clear the net and still spin in or if I hit the net cord it will spin in for a let
The flat ones there is less margin of error as the same clearance above the net on the flat serve might be long and if I hit net cord with a flatty serve it can bounce out
Someone as tall as Isner (who super tall) might be have more options and less margin of error