After watching Nadal at the Aus Open I don't get why he doesn't serve bigger. He is tall enough, has a great physique and yet his serve is on average 20- 30klms down on many of the top players. Surely his team should try an increase the effectiveness/speed of his serve.He basically has to fight for every point on his serve, as he struggles to pick up any free points off the serve. I think maybe his shoulders are a little too front on, but any ideas?