So the answer, in short bursts at least, is to use both.
Gailey said he wanted to use the two talented running backs in tandem at times this year, in order to maximize their effectiveness.
“You don’t want to do too much when they’re both in there because if you lose one of them then you’re without a big part of your package,” Gailey told Chris Brown of the team’s official website. “So you’re trying to construct enough to create problems for the defense, but not so much that you’re relying totally on having both of them at the same time.
“That’s a fine line that you walk creating offenses to be able to take advantage of both good players.”
Like the Bills, Jackson was off to a good start last year, averaging 5.5 yards per carry, and showing an impressive ability to make plays as a receiver. But when he broke his right fibula in Week 11, Spiller didn’t miss a beat, producing at a near-Jackson level, with four 100-yards from scrimmage games and five touchdowns over the last five weeks.
Having a pair of backs who can average more than 5.0 yards per carry creates its own problems, and Gailey’s up-front about the challenge.
“I can promise you this, we will not make everybody happy,” Gailey said. “That will not happen this year. The only thing that will make everybody happy is winning. That’s what the goal is, to come up with plans that incorporate everybody’s abilities that allow us to win.
“Other than that I can’t predict what’s going to happen as far as percentages for their touches.”
Spiller has the kind of open-field ability to split wide, but both backs have shown they could be the guy if need be. Managing their expectations will be central to Gailey’s job this year, because if he can keep them focused on team goals, there’s a chance they could give the Bills offense the kind of balance it needs.