It's the Forearm, Stupid!
We're innundated with advice on how to best exercsie to play tennis.
All important, no doubt, but remember Rod Laver's left, racket, forearm was reportedly twice the size of his right.
Take a look at this series of my photos. to see the definition in players' forearms.
Photos are of Serena Williams, John Isner, Novak Djokovic, Juan Martin del Potro, Rafael Nadal and Milos Raonic.