I guess I mean how they move as well as strokes... you know what I mean?... smooth, fluid, great rythym, graceful... as opposed to, say, I don't know, Roddick, or del Potro, and a lot of those ball bashing, slightly ungainly, and often quite big pro guys. So who is like the most super-smooth, "poetry in motion" pro?... Or put it another way, if you were advising someone a player to study for the specific qualities of smoothness, fluidity, rythym, grace, etc, who's the man? Thanks R.