It is true, the agressor will have an advantage in the scoring more times than not. But it has to be effective agression and if you are the agressor and the guy moving backwards is hitting you twice as much as you are hitting him than that is not very effective.

Mayweather has mastered this style. If you look at his feet you will see that he is so quick that he is set up to punch the moment he stops moving. He dosn't take steps back it is more like he takes really quick hops back. His feet are almost alwais in position to throw that right. Ricky had some success at the beginning cuz he is also very quick on his feet and he was able to jump in before Mayweather could react. So what PBF did was time him and he really did time him perfectly.

Another thing that he does is that when you do jump on top of him befor he can react, he does'nt back away and leave himself open to punches as he moves back. He stays there and either holds you or works you inside, which you all now know he can sure hold his own, and actually makes the other guy back off and if the guy is not carefull he'll eat another right hand as he moves back. It is really great stuff.