Despite the NFL trending towards a pass happy league in the last several years, every season there are stars at the running back position who carry the load for their team. It's often been said that historically the prime year for a running back is at the age of 27.
Injuries aside, one of the most prolific rushers in the last 5 years has been Jamaal Charles of the Kansas City Chiefs...who is entering his 27 year old season (born December 27th, 1986). According to FootballGuys.com he's the #1 projected RB for fantasy football, and rightfully so. Last season he accounted for nearly 35% of the Chief's total offense, and if he can stay healthy you'd assume there's more of that to come in 2014. On a per attempt basis he has been in the Top 10 every season (including his rookie year).
Yards per Attempt*
(note: In 2011 Charles had 12 rushing attempts before a season ending injury)
In 2013 Charles also had a significant impact in the Chiefs passing game, amassing 693 yards receiving and an amazing 9.9 yards per reception. If we combine rushing and receiving yards, how does he compare to other running backs in the last 5 seasons?
Pretty solid company, his 2013 season is the leader in combined touchdowns and has the 7th best season in total yards from scrimmage.
I'm bullish on Jamaal Charles this season too, but the above grid is a cautionary tale. With the exception of Ray Rice in 2009 and Arian Foster in 2010, none of the other running backs were able to come close to their output the following season (on a per game basis), not even Adrian Peterson.
Granted Jamaal Charles' 2010 season came in at a very respectable 121 total YPG, and 2011 he was injured, but it just goes to show how difficult a repeat performance is. Coaches get more tape and defenses adjust...if the Chiefs use of Charles doesn't evolve, his 27 year old season might not be the peak of his career.