When you get to the middle and late rounds in your draft, you want to be looking for players with upward mobility. Players whose floor is as a serviceable third wide receiver or running back on your roster, but who are in the right circumstances to become Top 24 players at their position (or Top 12 from tight ends and quarterbacks). Except for maybe Andre Ellington, you're not going to want to draft these players in a position where your roster relies on them to have a breakout year. As late round picks, these players have the potential to exceed their draft position, and that's the game we're playing on draft day. Value and up-side.