Here’s a great use for your tennis videos.  Let’s say you’ve been recording your tennis matches and watching them and maybe you’ve noticed that your footwork isn’t all that you thought it should be.  Here’s a clip by Jorge Capestany on which he talks about counting the number of steps you take between hitting the ball.

Try doing this for yourself and see if you can come up with an average number.  As Jorge says, you can relate the number of steps you take to the level of play.