By John Turney
One of those things was called the "Marshall Faulk number". It was a metric meant to measure running backs who run the ball well and caught the ball well, at least closer in yardage than average backs. They'd take the rushing yards and the receiving yards and compute a harmonic mean.
According to Wikipedia—The harmonic mean can be expressed as the reciprocal of the arithmetic mean of the reciprocals of the given set of observations. As a simple example, the harmonic mean of 1, 4, and 4 is
Well, they began that in 1999 if memory serves and today we will update it. However, we did it by average rushing/receiving yards per game, not the season totals so it will better include players from the 14- and 12-game seasons.
Faulk dominates the top six but other great names are listed including Lenny Moore, Chuck Foreman, and others.
Here are all the players who averaged (harmonic mean) 58.0 yards per game.