London, UK CNN  —  If you’ve ever picked up a tennis racket and attempted to serve against an opponent, you’ll know just how hard a skill it is. It’s one thing to get the ball over the net and yet a whole other thing to even start thinking about speed and accuracy. It’s a technique that quickly separates the professionals from the amateurs and a skill which has become increasingly important in the modern game. Nowadays, both men and women are serving faster than ever before, with players