I looked at the 100 players with the most rushing yards in football history. Then, for each player, I calculated the average weighted RANY/A of the offenses he played on. As usual, to come up with a career grade, I gave more weight to a player’s best seasons. If a running back had 18% of his rushing yards come in one season, well his team’s RANY/A for that year was responsible for 18% of his career RANY/A grade.
For example, in 2001, the good Jake Plummer showed up for the Cardinals, and Arizona had a RANY/A of +0.53. But since Thomas Jones rushed for only 380 yards that year — just 3.6% of his career total — only 3.6% of his career RANY/A is based on the +0.53. Conversely, Jones set a career high with 1,402 rushing yards in ’09 for the Jets, representing 13.2% of his career total. New York, behind a rookie Mark Sanchez, had a RANY/A of -1.69 that year, which matters a lot more when calculating Jones’ career grade. In fact, Jones played with bad passing offenses for most of his career: as it turns out, among all players in the top 100, it’s Jones who played with the worst passing offenses in his career. [click to continue…]