I've been trying to work on my serve and I'm confused on the purpose of the non hitting arm. iIknow you use that arm to throw the ball and it stays up until you're ready to hit your serve, but what happens afterwards?? I watched my serve on video and I just let my left hand drop down completely and it just dangles there by my side. I watch the pros serve and i see them tuck it in an "L" shape towards their stomach. What is the purpose of this? Will it help me serve faster and more consistent or is it just preference? Thanks for all the help!