This article is part of a series in which I evaluate 2022 rookie running backs solely on their ability to run the ball. The first installments can be found here. If you happened to already catch those and don’t need a refresher on my methodology, feel free to skip to the player-focused analysis below the picture of Iowa State’s Breece Hall a couple paragraphs down.
Outside the ability of whoever happens to be running the ball, there is a whole mess of variables that factor into the effectiveness of a given rushing attack; scheme, play-calling tendencies, opponent strength and scheme, weather, offensive line play, surrounding skill-position talent, etc. And given this entanglement, separating the contributions of the ball carrier from the offensive environment in which he operates is not a straightforward task. My approach to doing that is centered around measuring the degree to which a running back is over- or under-performing the per-carry output of the other running backs on his team.
Starting from the premise that good runners do more with what they are given than do bad runners, it stands to reason that, provided players are operating under generally the same conditions (like, for example, playing on the same team), better backs should produce more per carry than lesser backs. Using this logic, we can establish a baseline for comparing efficiency between players on the same team; for each running back, we can compare his performance (X) to the collective performance of every other running back on the team (Y). If X > Y (essentially, if dude is doing more with his carries than his teammates are with theirs), we can probably conclude that the player in question is a good player, at least to some relative degree.
Assuming that this is a sound method of evaluating running backs relative to their teammates, we can then extend our comparisons to players from other teams (we’re really just creating a baseline for efficiency comparisons similar to how Dominator Rating and other market share-based metrics create baselines for volume-based comparisons).
The key metrics I use to evaluate running back performance vs. that of their teammates are called Yards Per Carry+ and Chunk Rate+. I also like to use a metric called Breakaway Conversion Rate, but that is not a teammate-relative measure and we’ll therefore look into it separately.
The metrics are pretty straightforward: YPC+ is the degree to which a player over- or under-performs his teammates in yards per carry, and Chunk Rate+ is the degree to which a player over- or under-performs his teammates in rate of “chunk” runs (which I classify as runs of 10 yards or more). At a basic level, I want my running back prospects to find a way to produce more per carry than the other backs on the team, and part of that puzzle is navigating the line of scrimmage and extending runs into the secondary at a higher rate than his backfield mates. YPC+ and Chunk Rate+ measure the degree to which a player does both of these things.
THE METRICS
My personal favorite metric to use when evaluating running back prospect efficiency is Chunk Rate+, and over the course of 718 carries, Iowa State’s Breece Hall performed fairly consistently right around the output of the rest of his teammates in this area during his three seasons. On 186 carries in 2019, Hall outpaced other Cyclone runners by 0.89-percent in terms of 10-yard run rate, a mark in the 49th-percentile among backs drafted since 2007). He was then slightly outdone by them on 279 carries in 2020 (for a 34th-percentile rate of -0.79-percent) and on 253 carries as a junior in 2021 (-0.96-percent, 33rd-percentile). Overall, in terms of navigating the line of scrimmage and reaching the second level of defenses, a given carry from Hall was a bit less effective than a given carry from any other back on the team. It’s not like he was hurting the team. But his performance here obviously isn’t great, and the -0.41-percent career mark he posted in Chunk Rate+ ranks in the 37th-percentile.
Once he got to the second level though, Hall was pretty spectacular. After turning a mediocre 28.57-percent (41st-percentile) of his 10-yard runs into 20-yard runs as a freshman, Hall converted chunks into long gains at a Leonard Fournette-ian rate of 35.90-percent (72nd-percentile) as a sophomore, and at a Bryce Love-ian rate of 47.22-percent (97th-percentile) as a junior. His career Breakaway Conversion Rate sits in the 81st-percentile at 37.99-percent.
As his Chunk Rate numbers stayed fairly stable over his career, Hall’s overall YPC+ numbers rose with the tide of his improving performance in the open field. He outperformed other Iowa State backs by 0.09 yards per carry in 2019, by 0.60 in 2020, and by 1.11 in 2021 (32nd, 54th, and 75th-percentiles, respectively). His career 0.65 mark in YPC+ is in the 55th-percentile.
According to my infallible running model’s composite Rushing Efficiency Score (which accounts for all the metrics I’ve touched on in addition to overall team strength, offensive line play, rushing volume, strength of opponent, and backfield teammate quality), Hall is just above average among running back prospects going back to 2007, with a 52.5 out of 100.
Overall, the numbers here paint the picture of a runner who lacks some sort of nuance at the line of scrimmage (film study would tell you if that is vision, decision-making, decisiveness, agility, etc.) but is dangerous in the open-field. That particular blend of traits can be both effective and inconsistent, and this archetype of runner is one that I’ve identified as risky when projecting the translation of college success to the NFL per something I call:
THE JEREMY MCNICHOLS CORROLARY
Jeremy McNichols was the truth at Boise State, posting seasonal Dominator Ratings of 38.4-percent and 41.4-percent as a sophomore and junior, respectively. All while catching over 100 career passes on 11.2 yards per target, and averaging almost a yard more per carry than other Bronco running backs. After that, he went and ran a 4.49 at the Combine. By the numbers, McNichols was simply a dope ass prospect, and it’s difficult to reconcile that with his inability to really carve out a role in the NFL. Sometimes you just miss on guys, and that’s ok. But a closer look at the McNichols profile revealed something that I think is an indicator that a guy is balling off of athleticism in college while lacking the nuance as a runner that is necessary to thrive in the NFL.
That thing is what McNichols shares with a load of other guys — Kenneth Dixon, Darrynton Evans, Tevin Coleman, LaMichael James, Ryquell Armstead, Trent Richardson, and others — who were successful college backs who have struggled to fulfill their potential at the next level: inconsistent per carry output with overall efficiency that is buoyed by long runs (which can be fueled by raw athleticism). Frighteningly, this is something that McNichols also shares with Breece Hall.
TO THE INFALLIBLE RB MODEL
In fact, according to my running back model’s comp machine (which generates similarity scores between players — for the “pure runner” comp — on the basis of all the metrics that go into the composite Rushing Efficiency Score in addition to physical attributes like height, weight, and athletic testing numbers — I’m assuming Hall is running a 4.50 40 at 6-1, 220-pounds), McNichols is actually the player most similar to Hall:
Beyond the landmines, there are some success stories here in James Conner and Le’Veon Bell, and quality players like Jay Ajayi and Derrius Guice are also lurking just outside the top-10, but I don’t want to get out over my skis in declaring Hall a smash because he was good in college and comps to some RB1-level producers.
LAST WORD
Breece Hall is a quality prospect with a complete profile, but better have busted before him. Just as I would be “in” on a Jeremy McNichols clone if one was coming out of college this year, I am “in” on Hall near the top of rookie drafts in 2022, but I’m also here to tell you that you can’t say I didn’t warn you if he never really puts it together.