Does Size Really Matter for Running Back Prospects?

Every year the dynasty football community is enamored with running backs. They may have the shortest careers, but drafting a successful running back in the first round can have an immediate impact on your fantasy team’s success. On the flip side, using your pick on anything less than an immediate starter can decrease your team’s overall value.

So how does one find value at the position and avoid the pitfalls of despair? There are many methods that you can use, but my favorite metric—which happens to be the easiest metric to measure—is weight. The running back position is the position that will absorb the most punishment, so finding a guy who can take the most abuse often correlates to someone who will see the field more often, and avoid nagging injuries.

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If you draft a first-round running back, he should be someone that touches the ball 15-20 times per game. Someone touching the ball 20 times per game will get tackled or hit 20 or more times per game. Multiply that by the number of games in a season, in pre-season, and perhaps some postseason games, and that’s a lot of abuse. Factor in the amount of contact one will also receive during team practices, and we need a guy who can withstand a lot of punishment.

How Weight Relates to Running Back Fantasy Production

So how big does a running back need to be in order to increase their chances of success? Below is a list of every single first-round running back taken in all rookie dynasty drafts from 2013–2022, sorted by weight. Players who have finished in the top 10 multiple times are highlighted in yellow, while players who are seemingly on their way to multiple top-10 finishes are highlighted in orange.

If you look at this list, you’ll notice that the heavier they are, the greater the chance of success becomes. Players like Christian McCaffrey, Dalvin Cook, and Alvin Kamara have been great over the years because of their receiving ability. For example, Kamara has zero seasons of 1,000 or more yards rushing, but he’s averaged 72 receptions per year for his career. That is a good season for any wide receiver, let alone a running back.

The other piece of information you might discern is that there isn’t a single running back on this list below 200 pounds. Is that a coincidence? Do sub-200-pound backs have solid fantasy careers in the NFL?

That brings me to my next dataset. The following is a complete list of running backs who have participated in the NFL combine that weighed in under 200 pounds, including this year’s draft class. I will also highlight every single player who had a career in the NFL that consisted of multiple top-10 running back fantasy seasons.

Did you notice that not a single name is highlighted? You may recognize some names such as C.J. Spiller and Kendall Hunter and have vague memories of their successful NFL career, but these backs were oft-injured and only flashed at times. Their careers were subpar and cut short due to injury, as are most players on this list. Below is the same list, sorted by 40 times.

Sorting sub-200-pound backs by 40 times does separate the running backs who have had some success in their careers from those who have fizzled out, but ultimately it’s still a list of those who failed to dominate at the NFL level. There isn’t even a back on this list who has posted multiple top-25 seasons, let alone top-10.

Running Back Weight and 2023 Dynasty Rookie Drafts

Why am I bringing this up? Below is the current list of 2023 rookie running backs who have a first-round dynasty fantasy grade in mock drafts.

Both Jahmyr Gibbs and Devon Achane find themselves in uncharted territory. If mock drafts are correct, these backs will be the first sub-200-pound backs drafted in the first round of rookie drafts in my 15-year database. History suggests that being drafted in the first round of the fantasy draft will not happen. History also suggests that when they enter the NFL, they will fail to put up elite fantasy numbers.

I’m currently in the process of analyzing all rookie running backs for DLF and I rather like Gibbs. He runs hard and fast, but I can’t shake the thought that his landing spot and usage will ultimately dictate his actual value. I’m also concerned about how his size relates to those who played in the NFL before him, and worry about his long-term health for the duration of his career.

These are variables outside of my control, and I do not know if I want to spend a mid-first-round pick on a guy and hope that he can become the first back in recent history who can overcome obstacles that no other back has done. I’d rather take a chance on a different back or wide receiver than on Gibbs at this point, based on recent data.

Achane is in even worse territory. If you look at all backs who have entered the NFL at 190 pounds or less, only Tarik Cohen has done anything substantial fantasy-wise, and that’s nothing to throw a first-round value at. I love Achane's speed and balance at the point of contact, but he also goes down quickly when a defender gets a hand on him, and he won’t be able to outrun NFL defenses consistently like he did in college.

Tyjae Spears isn’t much different than these two, and he’s faced lighter competition his whole college career at Tulane. He’s much closer to the sub-200 group than he is to the successful players highlighted in yellow. Again, I’m looking elsewhere for a running back or switching to wide receiver if my options involve Spears when I’m on the clock.

Bijan Robinson and Zach Charbonnet fall in the “safe” area for now. They have the size to help carry the load if needed, and the talent necessary to become quality fantasy players. These are guys I’d much rather own than the other three if I was making my ranks today, not only based on size but other attributes that I’ll write about in great depth in future articles.

The Bottom Line

So does size matter? From a running back standpoint, I am shouting a defiant “YES!” It’s not enough that a back is quick and fast, but he must also be large enough to withstand the punishment of multiple NFL seasons. How do you feel? What are your thoughts? Let me know by following me on Twitter @MikeEHavens.