Footwork, why?

Hello, I’ve got an intriguing question. I pulled the following video in before and I immediately noticed with the guy the rough footwork, in which he sometimes presses at the brake gas and brake at the same time. Now I thought about why he does that, whether he just wants to keep the speed of the motor up or whether that has something to do with better delay or anything else? Does this bring a big advantage or would you be without just as fast? would like to know… Here’s the video:http://video.google.de/videoplay?… Greetings criZ