The 300-carry running back may be on his last legs, but specialized running backs are becoming increasingly popular as offenses look to create mismatches with players with positional flexibility. That makes it more important than ever to distinguish between personnel and formations. Bryan Knowles reviewed the former for 2018 a few weeks ago. This article will detail teams' frequency of and success on carries with one and two backs in their backfields.
The two are certainly related. The marked increase in 11 personnel—one running back and one tight end—across the league has mirrored the decline of runs from two-back formations.