Originally Posted by chico9166
What is "hard"? Ball velocity? Racquet head speed? Del po routinely hits the ball as "hard"/velocity as anyone on the planet. RHS? Not so much..... My own opinion, is that his backswing tends to compromise his ability to hit the kind of topspin that the big three can generate.....Than again, he also has a substantially higher contact point than the others that negates this disadvantage to a certain degree.
The vertical component can be improved
but it is NOT going to be twice
There are two issues:vertical RHS and vertical acceleration