I have been trying to develop a reliable and effective tennis serve for several weeks, with mixed results so far. I have experimented with various starting stances and tosses. I have noticed that when my toss has been at 12 o'clock, it has resulted in some sciatic pain on my right side, lower back down to thigh. Toss at 12:30-1:00 does not seem to have the same effect, but so far has not been as good a place for my serve. I reckon that some changes to my overall motion may allow me to do a 12 o'clock toss without the side effects. Perhaps I need to do some knee bending and stuff. Got to try and figure that out. Has anyone else had a similar experience ?