Long ago, when the world was young, there was a way to get from here to there. By zeppelin. It was all the rage.
Earlier, the preferred way to go was by stagecoach. Or by burrow. Or, if you could avoid the icebergs, by ocean liner.
Also, back in the day, there was another way to move.
It was called "by running back."
In an earlier NFL, this was how teams chose to move downfield. It was bloodier, and it was more brutal, but the teams of the day were kind of fond of it. It allowed stronger teams to physically push around weaker teams, and it made stars out of the men who endured collisions along the way.
Then all the rules were changed to value the passers, and the world fell out of love with running backs, and the NFL looked more like fireworks than wagon trains. And doesn't everyone prefer to fly than to drive?
That is, until you run into a couple of old-school guys who just ran their teams all the way to the Super Bowl.