McCaffrey isn't a scat back/pure "speedster" though. You draft those in the 3rd or 4th round. You draft the McCaffrey, Cook, Mixon types early... look at Zeke and Fournette, even Darren McFadden. The ones you draft early you count on to play 3 downs in the backfield and get a consistent 3-6 ypc between the tackles and convert the 3rd and 1's... usually between the tackles.