I have looked at Roddick's first serve and saw several instructional videos on the web. It seems that even Roddick at times will start with a separated foot stance, then move his feet together before 'jumping up' to hit a flat power serve. But then I've also seen other videos of Roddick where his feet are apart and he enter trophy stance, then launches from there with his feet apart rather than side by side. Is one better than the other? Is it just a matter of preference or are there particular uses to have one form over another? Perhaps I am missing something else as to why there's two versions of the pre-jump of a power serve (or the trophy stance, but not always looking like one). Thank you. And btw, I personally have found that going from feet apart to moving them together before 'jumping' gives me better % of getting in along with more power (but I'm not sure if that's because I just have bad form when doing the other version of the trophy stance).