So let's say you have a guy in your league who has both feet inside the baseline..on every serve. You notice this during warmup and when you see the guy playing on adjoining courts. The guy is a good guy, not a jerk or a cheeser with line calls or anything..maybe he just has no idea that he starts with both feet behind the line, but after his toss both feet slide way over the line. If he had a really weak serve it wouldn't matter, but his serve has become effective...it only clears that net by about 3 inches so that's another advantage he's gaining..that his flat hard serve with no margin for error probably wouldn't be clearing the net. Plus, he's developing a serve and volley game and he's gaining half a step on this. How do you go about addressing this without being a jerk...like bringing it up right before a match (gamey) right after a match (sore loser or winner). The first time I played him I actually took a few serves from his starting position and he didn't even get a racquet on them..trying to make a point. It didn't connect. The last time I played this guy we split sets, so I'm hoping I win and then I might bring it up.