Might as well work through the whole roster.
Starter: Marshawn Lynch
One amazing, historic, awesome in the literal sense run has caused a seismic shift in many Seahawks fans' perception of Marshawn Lynch. For most of the season, Lynch was damaging with bouts of outright catastrophe. That does not tell us whether Lynch is a good runner or not. He was part of the problem but could be part of the solution too. That might seem paradoxical, but it isn't.
Lynch is a big, bruising runner that doesn't shy from contact. Without blocking, his game became two yards and a pile of defeat. No good. With blocking, presumably, his initial acceleration will not be such a factor and his ability to cut back and break tackles will. So, with the 2010 Seahawks, Lynch was part of the problem. A quicker, more elusive back may have played better. With the 2011 Seahawks, assuming a revamped offensive line, and one that is actually coached (no offense to Golden Pat Ruel, but nevertheless), Lynch might be able to succeed, even excel.
Or so is the plan, but plan A should probably be paired with plan B. It would be a shame to say the least if Seattle built a smash mouth run game, but did not see improved results. Accepting that Seattle might not see improved results is smart planning. Runs by Lynch were the least valuable in football by EPA/P. Runs by Jamaal Charles were worth 0.17 EPA/P a play. Runs by Lynch were worth -0.19 EPA/P a play. That underscores just how much the Seahawks must improve as a team if they want to build the offense through running the football.
Change of Pace
Starter: Justin Forsett
Forsett started the season as an unorthodox feature back, and when that wasn't a riotous success, the Seahawks traded for someone that performed much, much worse. It's the kind of move that once upon time would have sent me into fits of loudmouthed protest. How can the superior player sit? HOW?
Well, depending on how you look at it, retro me may have a point. Forsett was more valuable per touch than Lynch, and also a more valuable receiver and pass blocker. Lynch may have commanded more attention from the defense, however we would define that, and that could have benefited the passing game, but that's all speculative, and for us outsiders at least, all but impossible to substantiate.
That all said, I like Forsett as a change of pace back because I think limiting his carries helps protect one of Seattle's better assets on offense. I don't believe that Forsett lacks durability simply because of his size, but his bruising style does not seem designed for a lengthy career.
Adding depth behind Forsett is less pressing. For one, he has succeeded--at least relatively--and so there is less concern whether he can or not. For another, a change of pace back is kind of depth by definition. If Seattle adds another rusher capable of shouldering starter carries, that player can also function as a change of pace back.
Michael Robinson is a free agent. With Bates out, the quarterback/special teams ace/rusher/zone blocking fullback may no longer have a place on this offense. Marcel Reece is a restricted free agent, and Seattle might try and workout a sweetheart deal to add the former Husky, but if not (and I wouldn't count on it) he provides the profile: big, fast, athletic and versatile.