Just out of pure curiosity, did they mention the average number of times Djokovic bounces the ball?
No they didn't.
I'm also similarly surprised not to see Roddick near the top of the second list, although I'm guessing the sample size of matches that he played in the tournament was not sufficient for inclusion in this investigation?
It says that "*min. five breaks between point and next serve" in the OP, which would imply that a sample of 5+ serves is sufficient for inclusion. But it does say in the article that they only measured the time for 54 players so he may not have been included.