Nadal's return game

[jhm36]

I was just browsing through the stats at the ATP site, and noticed something odd. While Nadal's service game stats hardly changed from the first half of this year to the last, his return game stats took a significant drop. This kind of drop in his return game did not happen last year when the tour moved from clay to grass and hard courts.

Any idea what happened? Why were people be better able to hold serve against Nadal this year than last during the second half of the season? Could it be that people are getting less intimidated by Nadal and feel more comfortable and relaxed while serving? Maybe Nadal is feeling the pain of his intense playing style and is saving a bit of energy on return games so that he can give it his all while serving? Maybe people realize better now that you need to serve big to stay in games with him and are doing so?

I've never looked for this sort of pattern before and really have no idea what could be the reason for this drop, nor how common/rare this thing is on the pro tour. Maybe it's common as dirt and happens to everyone. Anybody know more on the subject?

[federer]

They just take the ball on the raise. In Master Cup Shanghai, Blade basically destroy Nadal by hitting on the raise on every loopy forehand from Nadal. Nadal just has no time to response. I am very surprise that Federer didn't just copy what James Blade did. It's would have been a much easier semi-final for him.