Fantasy Football 2021: Who are the most underrated rookie running backs?

·6 min read

By Kevin Zatloukal, 4for4

Special to Yahoo Sports

We're now two months removed from the 2021 NFL draft, giving us dozens of new offensive players to consider for our fantasy teams. In this article, I will discuss some of the key rookie running backs to focus on going into fantasy drafts.

Our friends over at Dynasty League Football (DLF) have already compiled some post-draft rookie ADP, and, as expected, Najee Harris is not only the top running back off the board but also the top pick overall (in non-superflex leagues). While I would personally take Ja'Marr Chase before him, Harris scores incredibly well in all of my models and will undoubtedly be a workhorse back right away. You have every reason to expect Harris will put up fantasy points worthy of a top-two rookie pick (though do keep in mind that he is already 23 years old).

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Below, we will look at some of the running backs you can get later in fantasy drafts who also have a good chance to turn into productive assets for your dynasty team, and who could provide an impact in regular season-long and best ball.

Forecasting Running Back Success

As in the past two seasons, I estimate the odds of each player putting up a top-24 season within the first three years of their career by using a combination of three analytical models. The first is a standard statistical model (built using logistic regression), the second is a more sophisticated machine learning model and the third is a newer statistical model that projects using different criteria depending on each player's categorization as a passing, big or lighter running back. The odds reported below take an average of the individual predictions of the three models.

Last season, the model did a great job of identifying Antonio Gibson as the most undervalued player, as well as indicating that all five of the top options (Taylor, Akers, Dobbins, Swift, and Edwards-Helaire) were likely to be successful. That said, these rankings should not be used as the sole basis for ranking players. In particular, I combine them with other information such as John Paulsen's estimation of the player's opportunity at their landing spot in order to rank them into tiers and then look for the options that seem most undervalued where they are being drafted.

This season, here are the players that stand out to me as most undervalued (the full table of rankings appears at the bottom of the page):

Underrated rookie RBs for 2021. (Photo by
Underrated rookie RBs for 2021. (Photo by

The final column gives some information on where to target them in rookie drafts. Our friends at DLF have more complete ADP data showing where each player is usually taken.

Javonte Williams, Broncos

Those with an early/mid-first-round pick will be struggling with a decision between Travis Etienne and Javonte Williams. The model expects both players to be successful, and, of the two of them, Etienne is ranked higher.

Drafters agree with this and are taking Etienne earlier in drafts. I'm listing Williams here because it will cost less to move into the necessary spot to acquire him and because I think drafters are underrating his chances. While the models give higher scores to Etienne, I would note that the Broncos traded up to get Williams, which John Paulsen has found to be another good predictor of NFL success (one not incorporated into my models). Furthermore, while it would appear that Williams is blocked behind Melvin Gordon, Williams will undoubtedly see carries this year (as the Broncos used two backs last year) and Gordon's contract ends this season. If Williams plays well, I expect him to be the lead back next year.

Trey Sermon, 49ers or Michael Carter, Jets

The drop-off after the top three running backs is an enormous one. None of the other running backs are worthy of a first-round rookie pick, in my opinion. However, according to DLF, there is a good chance that Trey Sermon will be available in the early second round of dynasty drafts. If so, I'd be happy to take him there.

The 49ers moved up in the draft to take Sermon. As we discussed with Williams above, that is an extra indicator of future success. Sermon gets reasonable scores from all the models except the old statistical model, which is worth noting as that model has been the least accurate historically. Athletically, Sermon checks all the boxes with good height, weight, and a sub-7-second 3-cone time. He has was not hugely productive in college, but that could also be interpreted as a positive; with only 455 college carries, he may have more tread left on his tires than some other players. He was productive on a per-carry basis, however, averaged over 7 yards per carry in his last two seasons. While the combined models only give Sermon a 1-in-3 chance of success, he does seem worthy of an early second-round pick.

So far, in my own dynasty drafts, Sermon has been taken in the late first round. Michael Carter has also been available there. He scores similarly in the models and has an even better landing spot. In fact, Justin Edwards thinks that Carter is already the best running back on the Jets roster. If I end up in a draft where Carter falls to the second round instead of Sermon, I'd be happy to grab him here instead.

Kenneth Gainwell, Eagles

Of the three running backs in the third tier, the models are highest on Kenneth Gainwell, who is available in the late second round of dynasty drafts. While being behind Miles Sanders (who scored much higher in our models) is not ideal, Gainwell was a great pass catcher in college, so he could see some opportunity on third downs. That said, the depth chart is crowded with veterans like Kerryon Johnson, Boston Scott, and Jordan Howard (not to mention Jalen Hurts running it himself) and the team is not likely to score a lot of points, so the near-term situation looks bleak for Gainwell. If you have room to stash him on your taxi squad, his college production and athleticism say that he is worth a chance.

Kene Nwangwu, Vikings (dart throw)

Like Gainwell, Kene Nwangwu's near-term opportunity also looks somewhat bleak. He is stuck behind Dalvin Cook, a top-tier running back, and Alexander Mattison, a top-tier backup, on the Vikings roster. However, Nwangwu has a number of other attributes that make him worthy of a stash on your taxi squad: his draft slot is incredibly cheap (almost always available in the fourth round of dynasty drafts), he is an elite athlete (especially at 210 pounds) and he was a great special teams player, something that is predictive of NFL success. Fourth-round rookie picks, of course, are pure dart throws, but Nwangwu is as good an option as any in that range.

Complete Forecasts

For those interested, the table below shows the predictions from all models for all drafted receivers. In general, the combined model is more accurate. However, the predictions of the individual models are also interesting to look at:

2021 rookie running back to consider. (Photo by
2021 rookie running back to consider. (Photo by

Kevin is a Ph.D. computer scientist. His doctoral work at MIT was focused on quantum algorithms. During the fantasy offseason, he teaches computer science at the University of Washington, his alma mater.

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