Please critique my serve, I want to know what I can do to make it better/ what I should work on. I know one thing is to keep my left arm up longer right? Please note: serves may be only 80-90 mph(not sure) because I had played for 2 hours before this and yesturday for 2 hours(my arm was killing me). Also temperatures were in the 40's so the ball didn't go through the air that well. My serve was at about 80% of it's normal speed when I took these videos. What speed do you think these serves are? 60? http://vimeo.com/7155004 I know that I am off balance, but Im trying to work on it. Im also trying to work on landing inside the court fordwards not to the left side. I was rushed today because it started to rain and I didn't want to get soaked. I will make a video of my second serves some time this week And so far my shoulder isn't hurting. Im trying to get as much tennis in as I can before winter(1 month away).