Several people I have played recently have begun warming up by starting in the service box. I don't see the value in this. We don't volley, we just hit the ball softly back in forth in the box. I am more used to and comfortable with warming up at the baseline since these warm up rallies resemble most of the match play. I have done this kind of service box warm up before at clinics but I just don't get why it is done. Does anybody know why?