How can Baltimore Ravens actually use four running backs?

Double pro set:

I like to think of this as the “box” formation (different from the so-called “Notre Dame Box” formation that’s a variant of the Single Wing). Picture Lamar Jackson, under center, with a normal line in front of him (unlike the wonky Single Wing formation). Nothing too crazy yet, right? Then imagine all four running backs surrounding Jackson.

The typical Pro Set just sits the quarterback in the backfield with one running back on each side of him; but this places two to the left of the quarterback and two to the right, one pair right in front of the quarterback and one pair right behind. The extra man on the field (when you minus the quarterback, five linemen, and four backs) should actually be a wide receiver here, as this set allows the front two running backs to turn into blockers as the two rear running backs cross for a great RPO opportunity.

This would give someone like Marquise Brown the chance to rip the top off the defense as he runs down the field and either one of the two rear running backs takes a hand-off, or Lamar Jackson himself can rush through the gaps for big yardage. It’s even possible to use all of this motion as a distraction and nail a big pass play to the wide receiver. Again, options are the name of the game here.