Twice last week I really noticed Mack running where he seemed to slow his steps but carry his speed in the middle of the run. It was like he shifted into float mode. Then he hammers it back to full charge. It really must mess with other players trying to tackle him. It all happens at such a fast pace, at first thought you question if you even saw that. But I have gone back and seen it on video. It looks like he is slowing down when he changes his gate, but that is not what happens. It is a visual stunt that seems to confuse players by making them change their angle of attack. Just something interesting I will keep looking for.