Fred Jackson, at 32 years old, is still one of the most effective backs in the NFL.

You wanted him to go away. You thought heâ€™d go away. But he we are, in Week 16, and Fred Jackson is still running, almost like the Energizer Bunny wearing a blue and red Buffalo Bills uniform.

Fred Jackson was supposed to see a production dip this year, backing up the explosive, up-and-coming C.J. Spiller. It wasnâ€™t thought to be a full-blown 1-2 punch in Buffalo â€“ fantasy pundits figured, after extensive research, that C.J. Spiller would statistically blow Fred Jackson out of the water in 2013.

But after season-long health issues and a regression in overall effectiveness for Spiller, Fred Jackson has proved his worth. And he, at the age of 32, is doing it in historical fashion.

Jacksonâ€™s Advanced Metrics

Before we even dig into the numbers for running backs of his age, letâ€™s first take a look at how Fred Jackson is doing amongst the top backs in the league this season.

Player Rushes Rush NEP Rush NEP/Rush Career NFL Touches Age DeMarco Murray 178 30.35 0.17 608 25 LeSean McCoy 269 23.27 0.09 1,369 25 Rashad Jennings 150 11.07 0.07 465 28 Knowshon Moreno 225 15.04 0.07 979 26 Fred Jackson 174 10.38 0.06 1,357 32 Adrian Peterson 269 8.20 0.03 2,227 28 Jamaal Charles 246 6.84 0.03 1,247 26 Matt Forte 256 4.77 0.02 1,853 28 Giovani Bernard 145 2.68 0.02 194 22 Pierre Thomas 136 2.30 0.02 1,038 29

The table above consists of the top-10 100-plus carry running backs in effectiveness this season. Iâ€™ve included the number of rushes the particular player has seen, what that player has contributed towards his teamâ€™s output this season in terms of Net Expected Points (NEP), and how many points the back is adding with each rush. Then, in the final two columns, I looked at their total touches (rushes plus receptions) to date, along with the playerâ€™s age.

Letâ€™s note a few things here. First, NEP numbers are lower for running backs compared to passers and receivers because running the ball is far less effective than throwing it. That doesnâ€™t mean that rushing should be eliminated from the game of football, but it does tell us that throwing the football will yield more offensive success than running it. And thatâ€™s pretty evident when you watch the majority of NFL teams in todayâ€™s game.

Second, Fred Jackson has been the fifth-most effective volume back (though volume could have a much different definition to you) in the NFL this season. Think about that for a second. Last season, Jacksonâ€™s teammate, C.J. Spiller, ranked ahead of the 2,000-yard Adrian Peterson in Rushing NEP per Rush, capturing a 0.52 per rush average. This season, Jacksonâ€™s been the far superior back of the two, and heâ€™s doing it at 32 years of age!

I do want to point out the career NFL touches column, where Iâ€™ve listed the number of rush attempts plus the number of receptions each player has accumulated thus far in their careers. Of the 10 runners listed, Jackson ranks fourth in touches, behind Adrian Peterson, Matt Forte, and (barely) LeSean McCoy.

Some may find this important because, despite his age, Jackson hasnâ€™t been hit like the standard running back. However, a 32-year-old running back body compared to one in the mid-20s, regardless of volume, is going to bring an inherent disadvantage.

And keep in mind that F-Jax didnâ€™t start amassing NFL carries until he was 26. Prior to the NFL, he spent three years playing indoor football and in the NFL Europe, so his carry numbers are not necessarily as high as they should or would be had his talent (actually, his body size) been there when he first tried to make it to the NFL from Coe College (that's a real place).

The point here, aside from my rambling, is very simple: Despite being the running back grandpa, Fred Jackson has been nearly as effective as any running back in the league in 2013. Thatâ€™s how good his season has been.

Jacksonâ€™s Age and History

So we know one thing: Fred Jackson has been really efficient this season, regardless of age. But what happens when we look at what heâ€™s done this year and compare it to other running backs around his age in history?

To find the results, I used Fred Jacksonâ€™s current numbers and extrapolated his averages through the final two games of the season to come up with a reasonable finishing stat line for his 2013 campaign. In the end, he â€œshouldâ€ finish with 829 rushing yards (currently at 725) and 374 receiving yards (currently at 327). Of course he could go over or under those totals, but thatâ€™s where heâ€™d be expected to finish out given his averages.

To make this nice and clean, I decided to take a look at all running backs who had a season while they were 31 years or older with at least 800 rushing yards and 300 receiving yards. Jacksonâ€™s only 75 rushing yards away from hitting the 800-yard mark on the ground, while heâ€™s already topped the 300 yards receiving. The results were borderline shocking.

Player Year Age Team Rush Yards Rec. Yards Tiki Barber 2006 31 NYG 1,662 465 Walter Payton 1985 31 CHI 1,551 483 Walter Payton 1986 32 CHI 1,333 382 Tony Dorsett 1985 31 DAL 1,307 449 Ricky Watters 2000 31 SEA 1,242 613 James Brooks 1989 31 CIN 1,239 306 James Stewart 2002 31 DET 1,021 333 Floyd Little 1973 31 DEN 979 423 Garrison Hearst 2002 31 SFO 972 317 LaDainian Tomlinson 2010 31 NYJ 914 368

Over the course of NFL history, only 10 running backs who were 31 years of age or older have rushed the ball for 800 or more yards while accumulating at least 300 receiving yards. 10. Thatâ€™s it.

And while we've seen 38 seasons where a running back under the same age restrictions has simply rushed for 800 yards, we don't usually see the receiving combination among those runners.

Moreover, in recent history â€“ since 2000 â€“ this has happened five times. Take a look at the Rushing NEP scores of those five running backs, comparing them to Fred Jackson:

Player Year Age Team Rush NEP Rush NEP/Rush Tiki Barber 2006 31 NYG 24.54 0.07 Ricky Watters 2000 31 SEA -0.12 0.00 James Stewart 2002 31 DET -6.04 -0.03 Garrison Hearst 2002 31 SFO 11.12 0.05 LaDainian Tomlinson 2010 31 NYJ 2.09 0.01 Fred Jackson 2013 32 BUF 10.38 0.06

Of these five rushers, Fred Jackson ranks second in per rush efficiency, behind only 2006's Tiki Barber. It doesn't mean he was that close to Barber in terms of value for his team, as Tiki did contribute nearly 25 Expected Points for the Giants on the ground. Barberâ€™s final season of his career saw significant volume with a high efficiency score, something the rest of the running backs werenâ€™t really able to do.

But aside from Barberâ€™s fantastic season, you could argue that Fred Jackson, in 2013, is having the best multi-dimensional (rushing and receiving) season from a running back 31 years of age or older since the year 2000.

Iâ€™ll say it again: Thatâ€™s how good his season has been. Fred Jackson is an ageless wonder.