Downside: Touchdown Regression
Finding downside for someone like David Johnson is like searching for something wrong in the movie D2: The Mighty Ducks.
Good luck.
We can talk about touchdown regression, though, I suppose. Johnson finished last year with 16 rushing touchdowns, scoring on every 18.31 carries. The NFL average was a touchdown on every 31.54 attempts. He also scored on every 77.44 rushing yards, when the league's average for a running back was a touchdown for every 131.15 rushing yards. As good as Johnson is -- and as many opportunities as he's bound to see -- we shouldn't lock in that many touchdowns when projecting his 2017 season.
Even with the regression, DJ will be just fine. Draft him with one of your first two picks with as much confidence as Julie the Cat Gaffney had when she gloved Gunnar Stahl's shootout blast.