Photo: USA Today Sports

Welcome to Learning from History, where I dig into every fantasy season since 1985 to find historical comparisons for modern players.

Today, we're going to look at the player who inspired this series, Saquon Barkley. About a month ago I wondered if, knowing only what we knew at the time, there had ever been a player who was as valuable in dynasty leagues as Saquon Barkley is right now.

Again, the key here is "knowing what we knew at the time". Knowing what we know now, Jerry Rice as a rookie would have been worth way, way more than Barkley is today. But when Rice was a rookie we had no idea that he would one day unironically be getting "GOAT" tattoos. By the time LaDainian Tomlinson set the single-season touchdown record he was 27 and had just two more top-12 seasons left ahead of him.

This is the underlying tension. When a player is young and has his entire career ahead of him, he's typically risky and unproven. When a player is proven, half of his career value might already be behind him. Could anyone match the combination of youth and production that Barkley has already demonstrated?

Comparison #1: Age 21 Breakouts

On first glance, the two most relevant traits of Saquon Barkley are that he was extraordinarily young as a rookie and also was extraordinarily productive as a rookie. Based on those two traits, here's a list of every running back since 1985 to accumulate at least 80 points of fantasy value (roughly equivalent to an RB1 season) at age 21. I've also included their average per-year (APY) value from ages 22-24 and (for players who have retired already) how much total value they accumulated after their age-21 season.

Based on the average remaining career value of 805 combined with the 239 points of value he's already provided, Barkley might naively be projected to finish his career with about 1035 points of total fantasy value in PPR leagues. For a sense of scale, that would make him the 13th-best fantasy running back of the last 30+ years, just ahead of LeSean McCoy and Shaun Alexander, just behind Matt Forte and Adrian Peterson.

The success rate of this comp list is also remarkable. 10 out of 13 backs who topped 80 points of value at age 21 went on to average at least 80 points of value from ages 22-24. (Remember, 80 points of value roughly corresponds to an RB12 finish in a typical season.) That 10-out-of-13 figure includes Elliott, who could score zero points next year and still beat that average, and McCaffrey, who was so good at 22 he needs just one more point of value at ages 23 and 24 combined to reach that threshold.

One important thing to note: ideally, a list of comparisons will include a handful of players slightly better and a handful of players slightly worse. This isn't possible for Barkley because there were no players better than him at age 21. In this list (and every other list we're going to see), he sits at the top of the range of comps. Since production at age 21 is positively correlated with production after age 21 (small sample size, but the correlation coefficient among these retired comps is a robust 0.55), our expectations for Barkley should be higher than this list of comparable players suggests.

Comparison #2: Young Superstars

Maybe the most relevant fact about Barkley isn't how young he was last year, but how good he was. After all, only six out of the thirteen comps on the last list provided even half as much value as Barkley at age 21. Let's look instead at a list of backs who topped 200 points or value at age 23 or younger.

A couple notes before we dive in. First, Edgerrin James makes the list at both 21 and 22. I've included only his Age 21 season as most comparable so he doesn't skew the averages. Second, the "average value per year over the next three years" for Todd Gurley currently only includes one season worth of data (his 2018). I've weighted him appropriately when calculating the total sample average of 160.9 points of value. Third, yes, we really saw eight running backs accomplish this in the 33 years from 1985 to 2017 and three more accomplish it in 2018 alone. Yes, that's crazy.

Now, on to the comps. In this case, the group averaged 160.9 points of value over their next three seasons, which in a typical year is roughly equivalent to an RB4 or RB5 overall finish. All eight backs averaged about 100 points of value or more, which means everyone was a solid top-12 back going forward. Collectively, the backs in this sample who have already retired averaged about 995.1 points of value remaining, which combined with the 239 points of value Barkley has already produced would give him about 1235 points of value for his career, good enough to make him the 8th-best fantasy RB in our 34-year sample.

(And again, note that the fact that Barkley is younger than all of these comps except for James means we should naively expect him to have more remaining career in front of him than the average comp. Similarly, the fact that he was drafted higher than all of these comps suggests we should naively expect that he's more talented on average, too.)

Comparison #3: Highly-drafted Successes

There's one last fact that seems relevant about Saquon Barkley: he was drafted with the #2 overall pick in the 2018 NFL draft, the third-highest a back has been drafted in our sample after #1 picks Bo Jackson and Ki-Jana Carter (who... were not very productive as rookies). Here's a list of rookie running backs to produce at least 120 points of value sorted by where they were drafted.

I've highlighted the four players who are likely still adding to their career value totals (with apologies to the ageless Adrian Peterson and the technically-still-in-the-league Doug Martin). Those four players are also excluded from the averages at the bottom of the list.

The epic bust that was Trent Richardson leaps off of that list, but even including him in the data, there was a strong correlation between draft position and post-rookie value. The top-5 draft picks on that list averaged 1205 points of value after their rookie year (a total that, if Barkley matches, would leave him as the fifth-best fantasy back since 1985 behind only Marshall Faulk, LaDainian Tomlinson, Emmitt Smith, and Barry Sanders). All top ten picks combined averaged 1094 points of value after their rookie year. (When adding Adrian Peterson to your list of comps brings down the average, you know you've got an insanely good list of comps.)

Backs selected between pick 31 (Doug Martin) and pick 74 (Curtis Martin), meanwhile, averaged 801 points of value after their rookie year. There were a few big hits (Curtis Martin and Ricky Watters finished as the 5th and 7th best fantasy backs since 1985, respectively), some more strong fantasy assets in Matt Forte, Clinton Portis, and Maurice Jones-Drew... and one more inexplicable bust in Doug Martin. (What was it about the 2012 NFL draft?)

Herschel Walker turned into a strong fantasy asset despite being picked in the 5th round... but Walker wasn't your typical 5th-round draft pick; he was drafted by the Cowboys just so they controlled his rights while he was playing in the rival USFL. Had Walker gone directly into the NFL from college, he almost certainly would have been a top-5 draft pick (and also produced a lot more career fantasy value, if his seasons in the USFL were anything to go by). Meanwhile, other late-round rookie surprises Alfred Morris and Mike Anderson were colossal disappointments, totaling less fantasy value in their entire remaining career than they had in their rookie season alone.

Final Thoughts

I've called Saquon Barkley a unicorn, and I think the description is apt. No player in the last 30+ years has been as young, as highly-drafted, and as productive. Edgerrin James is really the only player who comes close. The players who show up on his list of closest comparisons are a who's who of the greatest fantasy backs of the last 30 years, and based on what comparisons you use, the average expected outcome for Barkley's career would leave him retiring as anywhere from the 5th-10th most valuable fantasy back since 1985.

While his list of comps isn't perfect (surfacing names like Eric Metcalf, Trent Richards, and Doug Martin), the 10th percentile of his range of outcomes is Reggie Bush, whose 462.6 points of value remaining is roughly equivalent to three more RB5 finishes or six more RB12 finishes, a hit-rate among historical comps that I've never before seen matched. Meanwhile, the 90th percentile of his range of outcomes is somewhere just north of LaDainian Tomlinson, trailing only Marshall Faulk in the race for "best fantasy running back in history".