Adrian Peterson is joining the New Orleans Saints as a power runner who will jump into one of the most prolific passing offenses of this generation. On this occasion, it's worth revisiting where Peterson's skills stand at age 32 and why an honest assessment of his limitations helped lead to nearly two months on the free-agent market.
Peterson could one day be enshrined in the Pro Football Hall of Fame, but any team evaluating his potential for 2017 would no doubt have considered the following:
1. Use him on obvious passing downs at your own risk. Peterson was a willing but largely incapable pass-blocker during his career with the Minnesota Vikings. If he didn't figure it out in his first 10 NFL seasons, it's fair to wonder if he will now.
2. Relying on Peterson as a first- and second-down workhorse could backfire. (Fortunately for the Saints, they have Mark Ingram on their roster.) Peterson has missed at least 13 games in two of the past three seasons -- in 2016 because of a knee injury and in 2014 for NFL discipline -- and has played a 16-game season only once since 2012. Knee injuries have cost him games in at least three seasons. Though one might not be connected to the other, a big-picture look at his career arc clearly shows a decrease in availability over time.
3. Though Peterson has proved to be a unique physical talent, most recently in 2012 when he ran for a career-high 2,097 yards a year after tearing his ACL, history is not on his side. He turned 32 in March, and in 47 seasons since the NFL-AFL merger in 1970, there have been only 10 instances of a runner that old producing a 1,000-yard season.
4. Most NFL teams are phasing out Peterson's favored formations. Nearly 95 percent of his career carries have come when the quarterback was under center. He has only 132 attempts when the quarterback is in the shotgun, a formation most teams prefer now. Meanwhile, he has a notably better average per carry (4.91 yards) when running behind a lead blocker than he does when he was the single back in a formation (4.61 yards). (Research courtesy of ESPN Stats & Information's John McTigue.) Fortunately, the Saints use the shotgun and pistol less often than some teams; they ran 507 plays last season when the quarterback began under center, the fifth most in the league.
Consider this nothing more than a sober reminder about the limitations of an aging running back who has a history of knee injuries along with on-field imperfections that have grown increasingly relevant. They are issues, aside and apart of any concerns about his 2014 guilty plea to reckless assault involving his son, that any self-aware team needed to consider before signing him.
Make no mistake. Peterson has been one of the NFL's best offensive players over the past decade. When he was drafted in the first round in 2007, he was a breakaway runner in a bruiser's body. From 2007 through 2013, he produced a league-high 62 rushes of at least 25 yards, 15 more than the next-best player over that span (Chris Johnson).
Since the start of the 2014 season, however, Peterson has only seven such runs. Part of that dip can be attributed to the games he has missed. Game mortality must also be considered. Peterson is not nearly the long-distance threat he once was.
With all that said, Peterson could still make a difference for the right team in the right situation. As we all learned after his ACL injury, his drive to surpass expectations might be unequaled in the NFL. But no team is going to trust a player to elevate upon all reasonable projections. No one should, at least. I doubt the Saints are. You would think that pursuing Peterson as a free agent would have been a no-brainer, but clearly it was more complicated than that.