As I watched the Roddick vs Federer match yesterday and even as I'm watching JMDP vs Nadal right now, one thing out of many that occured to me is how infrequently the truly flat-hitters of the game win big matches. Add Berdych and Blake to that equation as well. They can hit hard and flat, but by the very nature of flat strokes there is very little margin for error - not taken at the right height and without proper length, its either long or going into the net. So the question is, why don't some of these pros add some topspin to their strokes and gain consistency on their ground game. Then as they settle into their match and loosen up, they can unleash some flat, hard-hit balls to make aggressive plays. Seems like there is no in-between for flat hitters. An example of this was Roddick from yesterday. Among other things that he cannot do well, he simply cannot create the angles Roger and Rafa create because he doesn't know how to vary his topspin - like adding more topspin when trying an acute cross-court angle. I see the same thing today with JMDP. He's trying to out hit Nadal from the baseline, but way too many balls netted or long because maintaining depth without adequate top spin is so hard. Do you agree with my assessment?