Can Adrian Peterson Catch Emmitt Smith?

[h=1]Can AP catch Emmitt Smith?[/h][h=3]Will Peterson break NFL's rushing record, or will record chase break him?[/h]By Scott Kacsmar | Football Outsiders
ESPN INSIDER

Few would debate Adrian Peterson being the NFL's best running back, but he may also deserve the title of the league's biggest dreamer. Peterson recently told the Minneapolis Star Tribune that he expects to break Emmitt Smith's career rushing record (18,355 yards) by Week 16 of the 2017 season. That's only 79 games away.

An ambitious Peterson is counting on a "couple 2,000-yard seasons" and has expressed in the past that a 2,500-yard season is on his to-do list. That type of historic season may be the only hope he has of reaching his goal. Smith's record becomes more daunting with each passing season in a NFL that continues to steer away from workhorse backs, older backs and running the ball in general.

Peterson has rushed for 8,849 yards through his age-27 season. Now 28, he trails Smith by 9,506 yards. No one has rushed for more yards after turning 28 than Smith (8,195). Peterson must be far and away the most productive runner ever after age 28 to break the career rushing record.

We have a few methods of calculating his odds, but they all involve Peterson doing things that have never done before. However, that is the very definition of a record, so let's not rest on holding that against him. Peterson is the most capable running back to enter the league in the post-Smith era, which makes him the most likely back to challenge the record.
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The Favorite Toy and Regression

Baseball sabermetrician Bill James created a "Favorite Toy" projection system in the 1980s to find the likelihood of a player reaching a milestone. In 2006, Doug Drinen of Pro-Football-Reference revisited this tool to find LaDainian Tomlinson's chance of breaking Smith's rushing record.

Applying this method to Peterson, the Vikings RB has about a 23.5 percent chance of breaking Smith's rushing record. This sounds way too high. If we ran 1,000 simulations of the rest of Peterson's career, it is not likely he would break the record more than 230 times. However, this was just a rough estimate.

We can build a regression model to predict how many yards a running back will produce after turning 28. This is based on how many carries and yards he had through age 27. We'll spare you the math, but using only retired backs with at least 600 carries before age 28, the line of best fit predicts Peterson will rush for 4,946 yards the rest of his career, giving him 13,795 and ranking No. 5 all time. Not bad, but well short of the record.

But the regression approach is problematic because so many players in the sample are not on Peterson's level. Only seven players have rushed for 2,000 yards, and players like Craig Heyward and Kevan Barlow certainly had no chance of doing so. That is why we must look at running back greatness in the later years of a player's career.

Age-Based Rushing Greatness and Future Decay

Keeping in mind the type of rarified air Peterson is going to have to enter in the coming years to break this record, here's a look at the top rushing season for each age ranging from 21 to 37.


<!-- begin inline 1 -->[h=4]Most NFL rushing yards by age (21-37)[/h]

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No back has claimed the rushing title for more than two ages, but the change in season length hurts players like Jim Brown and O.J. Simpson. While Peterson had the best age-27 season ever, his previous efforts were not as dominant. In order from ages 22 through 26, Peterson's rushing seasons have ranked 10th, third, 24th, 25th and 95th.

If Peterson matched the best rushing season by a running back for each age ranging from 28 to 37, then he would retire with a record 22,734 rushing yards. Applying the same concept for the top 10 seasons at each age range, Peterson would have to have at least the fourth-best season for each age to finish above 18,355 yards.


<!-- begin inline 2 -->[h=4]If Peterson had X-best Season at ...[/h]

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Being the fifth-best back ever for each of the next 10 years, Peterson would still fall short by 775 yards. This does not mean Peterson has to be at least the fourth-best back at each age to break the record. He could be first in the next four years (7,490 yards), finish ninth in the four years at ages 32-35 and retire with a record 18,369 yards.

The possibilities are almost endless, as we have no guarantee Peterson will play one more season or 10 more. You can come up with many different combinations to get Peterson the record as these are just historic milestones.

What we do have is an obvious decline in performance with age. No one has rushed for more than 1,347 yards in a season after turning 32. That's the age where 1,000-yard seasons start to be really hard to come by as only 11 have happened after that point.

The following chart displays the x-best rushing season by age where x ranges from one to 10, just like the data previously discussed. No non-fullback has carried the ball after turning 38.


The top three age-based rushing seasons distance themselves from the pack early on with the age-24 season as the highest peak for those three. Things start to go downhill for all around age 28, which is the point Peterson now enters in his career. Eventually all the numbers fall save for a few moments of surprising dominance (for example, Washington's John Riggins at age 34).

Peterson is not likely to have much success in his mid-30s, as the wear and tear on his body will be too severe by then. That's a big part of the reason some backs had success at those ages. They avoided the early punishment.

John Henry Johnson had only 826 career carries before he rushed for 1,141 yards at age 33. Riggins, who averaged 185 carries per year in his first 11 seasons, never had more than 260 carries in a season until 1983 when he was 34.

Then you have the bizarre case of Marcus Allen, who was a force early in his career, winning league MVP with 380 carries in 1985. Owner Al Davis had a vendetta against him, and Allen played sparingly during the middle of his career. By the time he went to Kansas City at age 33 in 1993, Allen's body was as fresh as an elite talent could be at that stage.

Peterson will not have such luxuries as the Vikings continue to ride him in their offense. He had 197 carries in the final eight regular-season games last year. That would be 394 carries in a full season. As Football Outsiders first determined years ago with "The Curse of 370," it's dangerous to give a running back that heavy of a workload. Forget about breaking records. Rushing Peterson for records could break him.

What Will Peterson Do?

It should not take more than two seasons for us to know if this is a debate still worth having. A possible expansion to an 18-game season could help Peterson, but it must come quickly. Part of what helped Smith set the record, beyond entering the league at age 21, was that he played his whole 15-year career with uninterrupted 16-game seasons. He also avoided the big injuries, which Peterson has already failed to do with a torn ACL in 2011.

Peterson does not need this record to lay claim as one of the best running backs in NFL history. Smith has the record, yet not many fans, especially outside of Dallas, would give him such a high distinction.
For all the error associated with some of the formulas we looked at here, Peterson rushing for 5,000 more yards to finish near the 14,000-yard mark actually sounds like the most probable outcome.

It would be great to see a serious contender for Smith's record, but the changing dynamics of the NFL make this one look unobtainable. One thing that we do know with certainty: In our lifetime, there will not be many players with the skill and determination to challenge this record like Peterson.

One major factor the story is not taking into account is the fact that 3 years or less from now the NFL is probably going to move to an 18 game season.

Those extra 2 games a year will be huge.
You may have to put an (*) next to his name when/if that happens but the odds of an 18 game season during a significant portion of the rest of his career is above 50%.

Smith had an amazing line, great offense and overall a much better team. I dont think AP will catch him

I'd say the chances are slimming - a bit.