The fourth step of the tennis serve is the knee bend. Your weight transfer and knee bend will help you "get your legs" into your serve later in the motion. The weight tranfer -- rocking from the front foot to the back foot to forward into the tennis court -- will also help you time your serve and develop some rhythm. The key to this particular part of the service preparation is to have your weight equally distributed on the balls of each foot by the time you reach maximum knee bend. Less