I wrote this a few years ago:
NFL's All Time Leading Rushers
Here are the top ten running backs in NFL History as ranked by total yardage and how they break down into the catagories of years played, games played, yardage gained, attempts, touchdowns and the averages. If you wonder who is the NFL's best ever running back, the fog may clear when you look at the averages.
Player Years Games Att Yards TD Yds/Att Yds/Game Att/TD TD/game
E. Smith 15 226 4409 18355 164 4.16 81.2 26.9 0.73
W. Payton 13 190 3838 16726 110 4.36 80.3 35.9 0.58
B. Sanders 10 153 3062 15269 99 4.99 99.8 30.9 0.65
E. Dickerson 11 146 2996 13259 90 4.43 90.8 33.3 0.62
T. Dorsett 12 173 2936 12739 77 4.34 73.6 38.1 0.45
J. Brown 9 118 2329 12312 106 5.29 104.3 22.0 0.90
M. Allen 16 221 3022 12243 123 4.05 55.4 24.6 0.56
. Harris 13 173 2949 12120 91 4.11 70.1 32.4 0.53
T. Thomas 13 182 2877 12074 65 4.20 66.3 44.3 0.36
J. Riggins 14 175 2916 11352 104 3.89 64.9 28.2 0.59
Late additions:
J. Bettis 12 179 3369 13294 82 3.95 74.3 41.1 0.46
C. Martin 10 156 3298 13336 85 4.04 85.5 38.8 0.54
What if they all had 300 carries in a season? Based on their career numbers:
Brown 1586 yards 14 TDs
Sanders 1496 yards 10 TDs
Dickerson 1328 yards 9 TDs
Payton 1307 yards 9 TDs
Dorsett 1302 yards 8 TDs
Thomas 1259 yards 7 TDs
Smith 1249 yards 11 TDs
Harris 1233 yards 9 TDs
Allen 1215 yards 12 TDs
Martin 1213 yards 8 TDs
Bettis 1184 yards 7 TDs
Riggins 1168 yards 11 TDs
Basically, Ruth = Brown = Chamberlain = Gretzy