Great observation from pro-football-reference blog:
"We don't need to speculate on what Emmitt would have done if he had played for a mediocre team. He did play for a mediocre team from 1998-2000, and what he did was amass more rushing yards from age 29-31 than any player in NFL history aside from Walter Payton and Curtis Martin (yes, I know, Sanders and Brown retired before their age 31 seasons). Most good-but-not-great running backs are struggling to hold a job at age 30. Emmitt was a top five rusher on a bad team."
I'll put Payton just behind Sanders and Brown. After those three, can't see anyone else close to Smith, so hard to accept the distance between the two is very much
(only real question is who rounds out the top five, Van Buren?)