As we continue our pre-Football Outsiders Almanac 2018 stat bonanza, we turn our attention to how offenses performed running with either one or two backs in the backfield. We're talking about I-formations, pro-sets and other relics of a bygone age.
As you might have gathered from our offensive personnel analysis, two-back sets aren't exactly popping up all over the place. Even when teams do put two running backs onto the field, they're splitting at least one of them out wide roughly 20 percent of the time. The percentage of running plays out of two-back sets has declined accordingly; it would be a massive tell if teams were always rushing fullbacks and H-backs onto the field every time they wanted to run the ball.