Pro Football Focus did a post on running back age of decline and declared Maurice Jones-Drew at 5th among running backs as a scenario that “reeks of potential disappointment for fantasy owners” and Adrian Peterson as the “poster child for decline and disappointment this year.”

I disagree with the methodology used, at least as it relates to the conclusions reached. It looked at points per game for backs that met certain criteria, to find a running back aging curve. That’s fine. It shows that the population of backs peaked at 25 and declined after that. But you can’t use general life expectancy data to predict what’s next for a running back still at his peak, like Jones-Drew was last year. I think the author excluded data points for retired players, but guys like Natrone Means or Karim Abdul-Jabbar have little to do with the next season for Jones-Drew.

I also have a problem with this statement:

“I also removed Marcus Allen and John Riggins from this data. Their impressive stats late in their careers create misleading spikes on the far right of the graphs as the sample sizes diminish.”

How is the career of Marcus Allen and John Riggins a misleading spike, as opposed to a data point? That is no more “misleading” than Terrell Davis tearing up a knee for 27 year old elite running backs, since over 90% of the best running backs from age 24 to 26 did not tear their knees up at age 27.

Anyway, to look at decline likelihood of top backs, I took all backs since 1990 who finished top 12 in standard fantasy points. I then sorted them by age, and next year production. Here is a summary of the Yr N Fantasy Points at a given age, then the results from Yr N+1, including the percentage who finished in the top 10 the following season, and the percentage that were outside the Top 25 in running back points a year later.

Now, remember, those ages are from the Top 12 finishes the year before, so Jones-Drew, Peterson, Chris Johnson, and Forte were 26 last year. The players that go from 24 to 25 have it rough. The players turning 27, though, are returning to the top 10 at about the same rate as the players younger than them. (48% of all players in sample who were 25 or younger finished in the top 10 a year later). The drop off comes going from age 27 to 28, where less than half return, and again at age 30, where it becomes rare (less than 20% finish in the top 10 a year later).

So, yes, while running backs tend to peak at 25 and 26, if they are still really good at 26, they tend not to fall off a cliff. Just like with mortality rates, you wouldn’t use average life expectancy data to assess whether a healthy 59 year old was going to survive at 60.

To assess Jones-Drew (and the others), I pulled the top fifty careers since the merger based on running back yards from scrimmage at age 24 to 26 (besides those who just turned 26 last year). I then sorted them by fantasy points at each age, and ran a similarity study to Jones-Drew, Peterson, Forte and Chris Johnson at each age based on difference in fantasy points. The results below are the 20 most similar players, weighted, to assess fantasy value at age 27.

Over half of Jones-Drew comps finished Top 5 at age 27. Jones-Drew has had over 1,600 yards from scrimmage each of the last three years, and his top six comps were Eric Dickerson, Shaun Alexander, Ahman Green, Thurman Thomas, Eddie George, and Barry Sanders. Only Ahman Green finished outside the top three the next season.

Adrian Peterson’s comps probably overstate his outlook. His knee injury is partially reflected in those numbers, since his age 26 season was cut short. We see that players with a decline at age 26, like Peterson and Johnson, are not projected as well as Jones-Drew. Forte, who just signed the contract extension that he has wanted for so long, projects reasonably well also.

Still, I talked about how I was bullish on Peterson as well. I think he’s probably properly valued at RB9 range. If not him, then who? The thing about throwing out isolated examples of average draft position and finish is we can do that for any age. How did Steve Slaton or Laurence Maroney or Reggie Bush do when they were drafted in the top 12 picks at the position? What about Ryan Mathews? But rather than talk about isolated examples, I went through the last five years of average draft positions, and backs drafted in the top 16 at the position. Overall, once we account for draft position, there was no difference between backs who were 27 to 29 and those 26 or younger. Individual cases, of course, varied. (Alexander, Tomlinson and Westbrook were the only three drafted at age 30 in the top 16, and they all struggled).

The thing about draft position is that the majority “underperform” their draft position at all ages. The average pick in the RB4 to RB6 range the last five years? Only 27% finished in the Top 10, while 20% finished outside the Top 25. That’s where Jones-Drew is going, and his age and production comps vastly outperformed that. If not for a strong top of the draft with three backs, in their prime ages and with elite recent production, Jones-Drew would go higher.

Down at RB14 to RB16, almost half (7 of 15) finished outside the top 25 in running back rankings, and only 20% finished in the top 10. I know Peterson is a risk, but do you really think his median result is a finish of around RB24? I don’t. I more down on Chris Johnson if he is going in the top six, because of his decline from 24 to 26.

Jones-Drew is still in his prime, though, and has yet to show the decline. I know this because he just went for almost 2,000 yards from scrimmage and double digit touchdowns on a team that was dead last in passing efficiency. In the past, I talked about how backs who can do well on poor passing efficiency teams hold their value better the next year. Jones-Drew just put together the best season ever by a back on the worst passing team.

So, could he snap a knee and be done? Sure. I wouldn’t wager on it being the most likely scenario, though.

[photo via US Presswire]