Rob,
The head is irrelevent after the ball is released....where ever your nose goes so will your back side, which has the ball in it....forward hand speed is important or should I say impairative (sp?)....if you don't have forward hand speed it makes if very difficult to get the ball to do what you want as well as locate it....I think if you look at video of successful MLB pitchers you will find that a great majority keep their nose on the catcher at least untill after they release the ball...if the head or any other part of the front side leaves early it will affect what the arm does...ie. it will not promote forward hand speed, can cause you to push the ball etc.....and with out that you can't throw CB's,SL's, Split's, CH's(w/ armside run/sink) or sinkers properly....