Okay this might seem off the wall, but there are some crazy gimmic out there. so here is what I was thinking. What if there was a to fill the inside with some sort of fuild. (Not completely) My thinking was that in ready position (and possibly on volleys) the fluid would be in the handle and thus making the racquet head light, and when swinging on a serve or groundstrokes the fluid would be pushed to the head of the racquet and give it a higher swing weight. Why you ask? Maybe you would have some benefits of both head lightness and head heaviness. Just some random thoughts... what do you think?