Framing flat serves

[OvertheFence]

Whenever I try to hit a flat serve, I usually shank it or it flies long. Is this framing because Im using the wrong grip? I use somewhere between a continental and easter BH. Should I switch to continental/eastern FH?

 

[stormholloway]

I've been doing that. I think this is an issue about pronation. Pronation turns the racquet over. If you don't do it, or do it poorly, you will shank the ball.

This does a decent job of showing the idea:
http://www.youtube.com/watch?v=4DpptgXq5j4