During the 2013 season, the Buffalo Bills relied mostly on veteran runner Fred Jackson as their short-yardage and goal line back. They finished the season ranked 29th in both third down efficiency (34.0 percent) and red zone efficiency (scoring a touchdown on 47.7 percent of red zone possessions), and one major factor in those rankings was the team's general ineffectiveness in those specific "big back" situations.
Which is not to say, of course, that Jackson is no longer an efficient runner. Far from it; at 33, he is still a productive player in the league, and one of the team's most important figures on offense, especially given the group's overall youth. That big back role is just not really Jackson's jam, despite his setting a career high with nine rushing touchdowns last year.
In fact, the Bills began to admit as much in the second half of the season, when a few of Jackson's short-yardage touches started to go to fullback Frank Summers (19 touches, 125 yards, two touchdowns last year). That admission continued this offseason with the free agent signing of 233-pound situational back Anthony Dixon, and entering training camp, the role of the short-yardage back is one of the more compelling battles to keep track of.
Fred Jackson: The further Jackson traverses into his 30s, the harder he hits the weight room to better withstand the rigors of a NFL season. Jackson is still more of an open-field slasher than he is a pile-pusher, but a bigger Jackson still makes him a viable short-yardage option. Not all of the team's problems in these circumstances can be attributed to the guy carrying the ball, of course, and we've seen Jackson move the sticks or score enough times to know that the Bills could do far worse in this role.
Anthony Dixon: Buried behind Frank Gore and a decided third option behind second back Kendall Hunter for most of his four seasons in San Francisco, Dixon signed a three-year deal with the Bills this past March. He saw some short-yardage and goal line work with the 49ers, scoring two touchdowns in each of his four NFL seasons, and offers a bit more power than Jackson can provide.
Frank Summers: He was the Bills' fullback last season, but came into the NFL in 2009 as a back that averaged 16 carries per game in his two seasons at UNLV. He made the most out of a very limited sample size of touches in 2013, including on the ground, and given that he is the best pure lead blocker on the roster, he'll at least merit consideration in this battle, despite the increase in competition and the difference in abilities between them.
Of these three contenders, only Jackson is guaranteed a significant amount of playing time within the context of the offense. He will continue to see a large number of reps in the backfield, particularly in third down passing situations, where his blitz pickup abilities are valued. If the Bills want a short-yardage specialist, then, they'll need to make room for that role in the offense.
Fullbacks played on just 21 percent of Buffalo's offensive snaps last season, and that was predominantly a blocking role. The Bills also seem destined to expand the role of the running back in their offense - they typically only had one on the field last season, but have more mouths to feed there this season (and also simply need to have Spiller on the field more) - which will eat into the number of reps for not just the fullback, but tight ends and potentially receivers, as well.
An interesting wrinkle to this conversation to keep an eye on is whether or not the Bills give Dixon a look as a lead blocker this summer. He did it from time to time in San Francisco, but he's much more runner than blocker. Still, if the Bills don't see much of a drop-off between Summers and Dixon in the blocking department, then Dixon might have that role all to himself, and the short-yardage stuff can be worked in naturally from there.
Predictability was also an issue for Buffalo's offense last season, so while this role would be a relatively small one within the broad picture of the scheme, the team may not be comfortable giving all of those carries to one guy. Jackson will almost certainly continue to see touches in these situations, even if they're a minority share, so the two names to watch here are clearly Summers and Dixon, and not necessarily in that order.
More than anything, however, the Bills need that go-to guy on third and short if they want to keep the chains moving, and Nathaniel Hackett's desired play counts as high as possible.