How does offensive system dictate the size of an offensive line?

A few weeks ago I wondered if there were strategic reasons why all offenses don’t HUNH. I argued that one potential reason might be that offensive linemen are specialized by size, weight, and strength depending on the offensive scheme the team runs. So hypothetically, pro-style teams might recruit and develop bigger and stronger linemen over leaner and quicker ones.

I tested that this week by choosing a total of 27 teams that best represent four basic offensive styles – Pro, spread-to-run, spread-to-pass, and (for fun, really) option – and then comparing the average weights of their offensive linemen . Rather than just doing a random sample of 30 teams, I tried to pick teams that were most representative of a particular offensive scheme, since many offenses have multiple styles and packages. These teams, at least more than their peers, invested fully in a particular offensive style:

This isn’t perfect, and each team is somewhere along a continuum for their style. For instance, Clemson is likely the least purely spread-to-run offense in that group, with Chad Morris incorporating many spread-to-pass elements and play staples. Texas A&M, likewise, is built by air-raid disciples that are more happy running packaged run/pass options than just going all-pass all the time.  The same could be said about Baylor.

However, these teams best exemplified a particular offensive style. Many teams have shotgun-based, spread-to-run packages, but don’t run them frequently enough to fit into a single offensive category (i.e. South Carolina).

After choosing the example teams, I then calculated the average weight of their offensive linemen. Because I had a categorical independent variable with more than two levels (offensive scheme) I split the variable into four dummy variables, and then ran a regression with three of them, comparing them with pro-style teams as my reference level:

Despite being an average of six pounds lighter than pro-style teams’ offensive lines (which average 303.5 pounds), spread-to-run teams were not (statistically) significantly different than pro-style teams. Pro-style teams weighed the most on average, but only significantly more than option teams – and this likely has more to do with military academy physical restrictions than anything else. Spread-to-pass offensive lines were negligibly lighter than pro-style lines.

So, unless you’re a military academy running the triple option, your offensive linemen all likely fall into a similar weight range. However, it’s true that weight does not equal conditioning, so it’s possible we’d see differences between spread-to-run and pro-style offensive lines if we asked them to do shuttle runs or the 40. While keeping all those limitations in mind, this does call into question just how physically specialized pro-style offensive linemen need to be for particular offenses.

Finally, just in case you’re curious, here are the regression results when using triple option teams as the reference level: