Philadelphia, PA (Sports Network) -
There is a well-known theory running about fantasy football owners and experts, which says that a running back who carries the ball 370-or-more times in the regular season, or 390 times including playoffs, will see a drastic decrease in production the following season.
According to a study by Football Outsiders, the drop in rushing yards is significant - 35%, while the drop in yards-per-carry is 8%.
Looking at the final standings for the 2008-09 NFL season we see Atlanta's Michael Turner at the top of the "rushing attempts" category with 376 carries last season for 1,699 yards and 17 touchdowns. He also had 18 carries in a playoff loss to Arizona which puts him over 390 carries for the season.
"All Day" Adrian Peterson was second with 363 attempts, but fortunately for believers of this theory, he had just 20 carries in his team's playoff loss to Philadelphia, leaving him just below the 370/390 carries plateau (more about 300-369 carries later).
Using the "FO" theory, Turner is likely to post yardage totals in 2009-10 of around 1,190 yards and 4.1 yards-per-carry. Those numbers aren't quite worthy of a No.2 or No.3 overall selection, so the question we must ask ourselves is - "Is the Rule of 370 valid?"
There is certainly some anecdotal evidence to back the theory. Jamal Anderson (1998), Terrell Davis (1998) and Edgerrin James (2000) all suffered knee injuries after their heavy workloads. Larry Johnson broke his foot the year after carrying the ball a ridiculous 429 times (including playoffs) in 2006 and Shaun Alexander broke his foot after carrying the ball 430 times during the 2005 regular season and Super Bowl playoff run.
So there is some reason to fear picking Turner too high this coming season.
Even Peterson's 363 carries (383 including playoffs) should concern fantasy owners. The same Football Outsiders study showed running backs with between 300-369 carries encountering a 15% drop in yardage and 2% fall in yards-per-carry.
Obviously I would never tell you NOT to draft Peterson or Turner, but I am saying that later in the draft you should protect yourself by drafting their backups - in this case Jerious Norwood and Chester Taylor.
Last six running backs with 370 regular season rushing attempts