Welcome to another edition of Thunderdome! Hand-to-hand, no jury, no appeal, no parole: two men enter, one man leaves. Or at least something like that.

Our previous editions of Thunderdome -- first on the Rashaad Penny versus D’Andre Swift battle in the Philadelphia backfield and then on the Kenneth Walker versus Zach Charbonnet battle in the Seattle backfield -- dealt with situations in which the two players involved have never before played on the same team. Both Penny and Swift are new additions to the Eagles’ running back room, and Walker is an incumbent starter dealing with a new, second-round rookie as competition to his workload. By contrast, the situation in the Washington backfield is completely different: Antonio Gibson was himself an incumbent starter coming off a 300-touch season a year ago, with Brian Robinson a fourth-round rookie being brought in to complement Gibson’s contributions in some capacity, and now a year later, we have a season’s worth of data of these two players competing with each other for snaps and touches. In 2022, that competition was won by Robinson, who averaged 4.8 more touches per game than Gibson despite suffering a gun-shot wound two weeks before the season opener and thereby missing the valuable opening month of his rookie campaign on top of the uphill battle that came from having to assert himself in a rotation that, at that point, was led by veteran who’d gained over 1000 yards from scrimmage in both of his previous NFL seasons. Basically, we know how this thing played out in 2022, but considering that Gibson still managed to outscore Robinson on a per-game basis (they averaged 11.1 and 9.4 points, respectively, in PPR) and is currently selected ahead of him in seasonal best ball drafts on Underdog (he’s the RB34 to Robinson’s RB36) and valued more highly than him in dynasty (he’s the RB32 to Robinson’s RB36 over at KeepTradeCut), it seems worth reconsidering how this situation might play out in 2023.

To that end, let’s explore the various strengths and weaknesses of the games of both Robinson and Gibson alongside the contextual elements that exist in their shared offense.

Even at this relatively early point in these players’ careers, we have a pretty clear idea of the sort of runners they each are. Gibson produced dynamically as a rookie, averaging 4.68 yards per carry, posting a 125.0% Box-Adjusted Efficiency Rating, and gaining 0.14 yards over expected per rushing attempt in that season, numbers that each land in at least the 66th percentile among all NFL runners in the last seven years. Those marks were posted in Gibson’s first season as a full-time running back after having played wide receiver at Memphis, but after that encouraging performance, he hasn’t been nearly as impressive: 2021 saw him post sub-50th-percentile marks in each of raw yards per carry, Relative Success Rate, and RYOE per attempt, indications of subpar performance that -- combined with some struggles with ball security, pass-protection, and short-yardage running that I addressed in this video -- opened the door for the team to insert a player in Robinson who seemed able to supplement Gibson’s dynamism with reliable contributions in his more deficient areas.

Robinson came into the league with hype as a pass-blocker, zero fumbles on 597 collegiate carries, and a no-nonsense running style that saw him force missed tackles at a 71st-percentile per-carry rate according to PFF and churn out positive outcomes on his rushing attempts at a 70th-percentile rate according to RSR. Those things combined to make him the perfect remedy to the ails of a coaching staff that seemed to have become disenchanted with Gibson’s inconsistencies, so even though Robinson entered the 2022 season with less health, less experience, and less athletic juice than Gibson did, he won the primary ball-carrier role virtually immediately, earning more snaps and rushing attempts than Gibson during his week five NFL debut that came just a month-and-a-half after getting shot. As it turned out, he deserved that higher spot in the pecking order as well, as last season’s rushing efficiency numbers for each back demonstrate:

The 24th-ranked run-blocking offensive line (according to PFF) meant that neither player produced very efficiently overall, but in a head-to-head comparison, Robinson was clearly the more effective runner, especially in terms of providing reliable output on a down-to-down basis. And, as Graham Barfield eloquently points out, Robinson was better late in the season after some understandable struggles in his first few weeks of NFL action:

Further context is lent to this small-sample improvement by Corey Buschlen, who points out that Robinson’s late-season increase in raw yards per carry was accompanied by sizable jumps in his PFF rushing grade and rate of missed tackles forced per attempt. Basically, while Robinson was already a better runner than Gibson as a rookie on aggregate, even the numbers that reflect that reality were subdued by a career-opening slog as he acclimated to a higher level of competition while simultaneously recovering from gunshot wounds. It’s entirely possible -- and even seems likely -- that his rookie performance was not reflective of his actual abilities, in which case we haven’t yet seen the best Robinson has to offer as a starting-quality NFL pounder.

The same does not seem to be true of Gibson, who has seen his effectiveness as a rusher decline in each season of his pro career and has already had his role scaled back after receiving an audition as a workhorse runner in year two. Now, the upside for Gibson manifests itself almost solely through offseason puff pieces that have billed him as the Commanders’ version of Christian McCaffrey, or, most recently, as the beneficiary of a higher-octane offense under new offensive coordinator Eric Bieniemy.

The transition from Scott Turner, who coordinator this offense from 2020 to 2022, to Bieniemy, who had been the non-play-calling coordinator in Kansas City since 2018, should come with a more pass-heavy approach: in the last two seasons, Washington had pass/run ratios that were the 8th and 12th, respectively, most run-heavy in the league, while the Chiefs were in the bottom ten in that area in both years. Having Patrick Mahomes at quarterback certainly has something to do with those play-calling tendencies, but after the Commanders called runs on 58.4% of plays in neutral game-script situations last season (according to rbsdm.com) -- the third-highest rate among all teams in the last five years -- there’s not really anywhere to go but up in the pass-rate department anyway.

That increase in pass plays will help Gibson more than it does Robinson, as the former wide receiver is an accomplished professional pass-catcher who has hauled in 124 balls so far in his NFL career while posting 75th-percentile Route Diversity and earning targets at an 86th-percentile-or-better RATE in each of the last two seasons. Robinson caught just nine passes on 12 targets as a rookie while posting Route Diversity and RATE marks in the 21st and 43rd percentiles, respectively, and only one of his targets came on something other than a basic, checkdown-type pass pattern. A bit more upside is reflected in his receiving usage at Alabama, but Gibson is clearly better suited to the primary pass-catching role in this offense.

Along with the departure of satellite back JD McKissic -- who’d hauled in 5.0, 3.9, and 3.4 receptions per game, respectively, in the last three years, and whose absence therefore means an opportunity for more receiving work for Gibson -- increased upside for Gibson in the passing game is supposed to be represented by the presumption that Bieniemy will implement a greater number of screen passes in the Washington offense than have been present in recent seasons. The numbers from Bieniemy’s time in Kansas City would seem to bear that out: the Chiefs targeted running backs on 85 screen passes from 2020 to 2022 while the Commanders did so on 73, and screens accounted for 26% of all targets to running backs in Kansas City during that time while making up only 17.7% of those to running backs in Washington. Considering that screens are easily the most efficient running back pass pattern -- backs average 4.86 yards per route run on screens compared to 1.06 yards on all other routes -- such a feature added to this offense should mean good things for Gibson, who is an explosive athlete capable of creating big plays from anywhere on the field.

JD McKissic has been an under-the-radar stud among pass-catching running backs in recent seasons, and his departure opens the door for Antonio Gibson to step into increased receiving volume.

Still, it’s also true that Kansas City’s running backs were not especially large parts of the overall passing game and were also not used particularly creatively on their relatively limited opportunities. The 42.6% route participation rate that Gibson enjoyed last season is close to the highest marks posted by any Chiefs runner during Bieniemy’s tenure as OC (Jerick McKinnon maxed out the group with a 47.9% rate last season), and McKissic’s rates of 64.4%, 59.0%, and 55.6%, respectively, in the last three years blow the Kansas City backs out of the water. Further, while Gibson (and McKissic) has run a diverse route tree and been targeted frequently on a per-route basis in recent seasons, running backs in Kansas City experienced the lowest collective Route Diversity in the entire league during Bieniemy’s time, and they were targeted at an 88.5% RATE that lands in the 31st percentile. Again, those target-distribution tendencies have something to do with having Mahomes at quarterback, but the evidence we have of Bieniemy as at least a co-architect of professional offenses doesn’t contain a lot of runners-as-receivers success stories. He’ll certainly shake things up a bit now that he’s out of Andy Reid’s shadow, but we have no way of knowing what his own sensibilities will look like until they manifest on the field, and right now, we’re basically hoping for a screen-fueled surge in Gibson’s receiving numbers despite participation rates and creative usage that seem destined to take a nose-dive. Maybe it all results in a net positive, but I don’t view that as a foregone conclusion.

Ultimately, I wouldn’t be surprised to see both Robinson and Gibson improve upon their per-game fantasy output from a year ago. Robinson should be better prepared to battle defenses after a contextually impressive but slow-going rookie season, Gibson stands to benefit from the departure of McKissic, and a Bieniemy boost to the offense as a whole would be the rising tide that lifts all boats after these guys had to do their best on a unit that was bottom-five in the league in yards per play in 2022. Shooting for the moon means opting for Gibson over Robinson in fantasy drafts, but I think the younger back is more likely to establish himself as a weekly fantasy starter than the veteran is. He already took Gibson’s job and played better after doing so, and given the research laid out in this fantastic article by Ryan Heath, it’s much more common for a second-year runner to ascend than it is for one entering his fourth season.