John Isner and Milos Raonic's Serves Up Close
Milos Raonic and John Isner are both big and big servers but their techniques and tactics differ substantially. Lets take a close look at both through a variety of slow-motion video techniques and photographs taken at several tournaments over the last three years.
The serve is one shot where you really can't tell what players are doing without using slow motion; it's simply too fast and too much is going on for the eye to catch.
Isner has the heaviest serve in tennis and because of that probably the best second serve, take a look at his technique and you can see why. John tosses the ball far in front of them hitting the ball 4 feet into the court and nearly 11 feet. He uses tremendous shoulder rotation often ending up with this palm literally facing straight up. This imparts huge rotation on the ball, which coupled with the way his height allows him to hit the ball down into the court, makes his serve jump off the court.
Raonic, by contrast, uses the platform stance like Pete Sampras or Roger Federer and tosses the ball on the side not as far into the court as Isner. Raonic's ball is not as heavy as that of Isner, but he has more variety including a very effective wide slice to the deuce court (a ball I don't believe is in Isner's repertoire) and wicked twist in the ad court particularly on the second serve.