When Mayock talks about quicker than fast, Riddick is that too a T.
Quicker than fast usually means this guy has a big discrepancy between their initial burst or in and out agility versus their straight-line speed. You see a guy like Tavon Austin whose agility is incredible you hope it translate to straight-line speed, and in fact it does. Riddick makes some of the most explosive moves in space but once he gets out, there isn't more giddy-up. Which isn't horrible because many NFL RBs are like that.