Stephen Dubner

They had been at the center of the game since it began in the mid-1800s.

It wasn't until 1906 that the forward pass was allowed in professional football.

The NFL was founded in 1920, and for its first few decades, passing was rare.

On the vast majority of plays, the ball was snapped to the quarterback, who would then hand it off to a running back.

who would follow the blocks of his offensive linemen to try to get through the defensive linemen.

It was not necessarily exciting.

Football was a slow and grinding affair.

Three yards and a cloud of dust was how people described it.

Perhaps not coincidentally, football was not very popular either.

The big American sports back then were baseball and boxing.

It wasn't until the 1960s and 70s, with the rise of the passing game, that football started to become the juggernaut it is today.

But for at least a couple more decades, running backs remained the star attraction.

The position has always required a certain amount of physical sacrifice.

So how long ago did you start thinking about this decline in the value of the running back?

Everybody, right?

And so the running backs...

They've had the biggest drop relative to any other position.

This season, the average salary of a starting quarterback in the NFL was just over $30 million.

The average for starting running backs, $7 million.

There are still plenty of running backs who are considered superstars.