I try to focus on the player, not the system. With his size and versatility, he would be a prospect on any college team.
I can't say I'm an expert on his game, but in some of the clips I watched (vs. Troy), he was often hit in the backfield early in the play. Not really his fault.
This is going back quite a bit, but Steven Jackson had a pretty poor YPC in his final college season and that was a red flag for me. However, it was really down to his system and supporting cast more than his lack of talent, as he ended up having a brilliant pro career. You can watch Adrian Peterson get demolished by USC in the NCAA title game for another example of this. If the system around you is constantly failing then you're not going to look as good as you really are. Even though Boise has a good recent history of yielding NFL RB prospects, that doesn't mean the team and run game are equivalent in every year.
Mattison is no Steven Jackson or Adrian Peterson (not even close), but I would try to isolate his qualities independent of the stats and uniform he wears. What I see is a big back who, while not overly explosive, has a nice north-south stride, good hands, and just enough quickness/agility to be effective. On run talent alone he may only be a day three guy and strictly a backup caliber talent (in fact, in many years his overall draft position would equate to the early 4th round rather than the late 3rd where he was taken). However, as I said, he has better receiving ability than the typical day three bruiser and that's likely why he got the slight bump in the draft, as the league values versatility in backs.
I took him with the #23 pick in a rookie draft today and it was less because I love his game and more because the alternatives on the board were grim. I'm realistic about his outlook. He's most likely a backup talent who lacks the dynamism to command a starting role, but who can step up and produce useful stats when needed. You could compare him to someone like Joique Bell or LeGarrette Blount. Neither is an ideal NFL starter, but both had periods of utility and FF relevance. I own Dalvin Cook in one league and think he's a decent back, but he is not big, not powerful, and has thus far has not been durable. As long as you don't go crazy overdrafting Mattison, he makes sense as a cheap dart throw who can potentially pop up and fill a RB2 slot in your lineup in spurts. If you have Cook already, the price to roster Mattison is probably going to be reasonable enough to make it worthwhile.
