I’ve watched most of Blake Corum’s eight games so far this season, but because Michigan is dedicated to blowing out every opponent they face in the slowest and least watchable fashion each weekend, and because I also like to get high, play 2k, and listen to Roc Marciano on Saturday mornings, my attention is generally not fully dialed in on the football game taking place on the 13-inch laptop screen sitting next to me on the couch. Because of that, my sense of how Corum has been playing in this return-from-injury campaign is tenuous and mostly informed by how his rushing efficiency metrics look, so I decided to grind some film to gain a clearer picture of how things are going.

The games I watched were the matchups with Rutgers and Minnesota in which Corum’s combined stat-line was 30-166-3 (so 5.53 yards per carry on 15 carries per game, fairly in line with his season-long averages of 5.45 and 13.9, respectively), so I theoretically saw a representative version of the player who has led the Wolverines’ backfield thus far in 2023. I want to share some insights that I gleaned and point out some key plays that I noticed across those two matchups, but let’s first start by bringing you up to speed with my understanding of Corum’s senior-year performance from before I watched that film, using data and compared to how he played in 2021 and 2022.

To set the stage for that understanding, we must contextualize Corum’s on-field performance in each of those seasons with the performance of the Michigan offensive line and the circumstances in which his carries took place, factors that I’ve chosen to illustrate via five metrics:

Here is how the relevant actors have fared in those areas in the last three seasons:

There are a few different moving parts here, but I think it’s clear that the circumstances of Corum’s carries have not changed significantly between his previous two seasons (especially 2022) and this one. Corum’s teammates have seen their collective efficiency tank this season, but while I don’t worship at the altar of Pro Football Focus, I do think it’s more likely that Donovan Edwards is simply stinking up the place enough to sandbag those numbers than it is that PFF is vastly overrating the performance of an entire offensive line group (and for what it’s worth, non-Corum and non-Edwards backs have averaged 4.68 yards per carry and succeeded on 46.8% of their attempts for Michigan this year). If that’s the case, then Corum is once again running behind an impressive run-blocking unit and into some of the most heavily-stacked defensive fronts of any back in college football (there are only three backs in the Power Five conferences who’ve faced more defenders in the box on their average rushing attempt than Corum has), and if that’s the case, then we can more or less safely compare his 2023 efficiency numbers with those he posted in 2021 and 2022 without pesky and subjective considerations about how much harder or easier things were for him in a given season.

With that out of the way, let’s look at Corum’s efficiency numbers -- separated into raw, team-relative, and through-contact categories -- from each of the last three years:

Overall, I think Corum’s per-carry output has been very similar this season as it was the previous two years. He’s succeeding on his attempts at the highest rate he ever has, he’s outdoing his collective teammates in terms of average yardage gained and rate of explosive plays as well as he ever has, and while raw measures of his play in those two areas reflect a drop-off in performance, Jerrick Backous’ RYOE tool over at campus2canton.com sides with the above team-relative marks in indicating that, situationally, Corum’s per-carry results this season are just as good they were in 2022 and 2021:

Corum got hot at the end of 2021, finishing with an RYOE per attempt average of 1.10 compared to 0.27 in 2022 and 0.69 so far in 2023, but around the 110-carry mark that Corum currently sits at, there’s not much to distinguish his performance in any of these seasons. From an on-field results standpoint, he’s the same guy this year as he was in 2022 and 2021.

Where he hasn’t been the same guy is versus contact. He was legitimately good at evading tackles and gaining yards after contact in 2022 and 2021, and he’s been legitimately bad at those things so far in 2023, something that my charting of his Rutgers and Minnesota games is on board with.

On a -1 to 1 scale representing the average level of success a running back achieves in physical encounters with defenders, here’s how Corum ranked among 27 runners (most from last year’s draft class) for whom I’ve charted a significant amount of carries prior to watching his 2023 film:

As you can see, Corum performed well above average both on aggregate and against each individual defensive position group across the 110 carries I’d charted from his 2021 and 2022 seasons, typically landing amid much bigger runners in each of these categories. With the 30 carries from the Rutgers and Minnesota games added to that sample, here’s how Corum’s cumulative numbers now rank:

Corum is still largely fine and even good in some of these areas, especially for a 5’8 running back who weighs substantially less than 220 pounds, and even though I didn’t notice while watching his recent games that he now looks markedly less powerful than he did a season ago, it’s kind of wild to incorporate those numbers into his full sample of carries and see just how much they drag down his averages. Maybe that’s evidence of a loss in explosiveness from his knee injury, maybe it’s the result of 30 semi-random carries’ worth of not powering through contact like he typically would, who knows. More film study will help distinguish between those two possibilities.

From a decision-making perspective, I did not notice a significant difference between pre- and post-injury Corum, to the point that it wouldn’t be instructive or even interesting to point out whatever small-sample distinctions I could make between his old and more recent film. He’s the same cerebral runner that he was before, which means he shows excellent vision, patience, and decisiveness on a carry-to-carry basis, especially on the gap runs that make up a large portion of his workload at Michigan.

Let’s highlight some of the things Corum does well with examples from the Rutgers and Minnesota games, starting with this 41-yard run against the Gophers:

It’s impressive in the first place to step out of a reaching tackle attempt at the line of scrimmage and then have the burst to immediately explode away from a pursuing linebacker, but Corum earned himself an extra 20 or so yards on this play by pressing behind #52 before cutting back outside, forcing the only defender who had a shot at making a play into engaging with a blocker. That’s intelligent and disciplined running in a spot where many backs would hit the jets and take their chances in a 1-on-1 situation around the 45-yard line.

With no viable cutback lanes on this play, Corum outruns his pullers to the outside and is presented with a 1-on-1 with a defensive back who has him dead to rights for a short gain. Corum hits him with a feint, forcing the defender to slow his pursuit and open his hips in anticipation of a full juke, which allows Corum to explode low off his back foot and toss a suddenly-flat-footed tackler to the side. There’s more than one way to skin a cat, but I thought the solution Corum found to this particular problem was creative in addition to being clearly effective.

The line of scrimmage work versus Rutgers on this next play is classic Corum:

Matt Waldman would point out that Corum could’ve pressed another half-step or so forward on this inside zone (duo? I think it’s inside zone but the analysis here applies either way) run, but I also think he’d approve of the overall process. The read to bounce wasn’t a difficult one, but Corum almost always does a good job of pressing to the line of scrimmage just enough to suck in those unblocked linebackers and create flat pursuit angles, which he uses here to reach the edge and turn the corner before letting his elusiveness earn him some extra yards outside the hashes. Read, press, go is the name of the game, and Corum plays it well (both at the line of scrimmage and in the open field, as we saw in our first clip).

On the above play, Corum shows that the reads and tight tracking he displays on a consistent basis are happening at the level of instinct. He’s a bull seeing a red endzone on this play, but he needs to thread the needle between avoiding the initial penetration and juking himself so far into the gap that the crashing linebacker will be able to drop him at the line of scrimmage in order to score, and he does it perfectly with no time to think. The little slide he hits keeps him tight to the back of #18 while preserving his momentum and allowing him to get low in his encounter with the linebacker, and from there it’s all legs and guts to get into the endzone.

We obviously see an example of the kind of power that Corum is still able to run with on that last play, and I think through the writing of this article I’ve formulated another hypothesis for why his missed tackles forced, yards after contact, and film-charting numbers show him to be a lesser runner through contact this season than he has been previously. Considering that Corum is now up to 213 pounds and is obviously jacked, I don’t think it’s power that’s missing from his game, but perhaps it’s lateral agility. Dead legs and jump cuts made up a large portion of Corum’s overall bag of evasive maneuvers in the 2021 and 2022 games that I initially charted of him, and I’m struggling to remember a good example of the same kind of hard cut made by him against Minnesota or Rutgers in 2023. That’s not to say there were zero of them or that those things are now completely absent from his game, but if they’ve become a diminished part of his game after being go-to aspects of his repertoire prior to injury, then it makes sense that he’d be breaking fewer tackles these days. Such a phenomenon could also negatively affect his power by lessening his ability to throw defenders off balance and minimize contact in the same way that he used to.

I’m looking forward to watching more of Corum’s 2023 film as it becomes available. For now, it’s clear to me that he’s a slightly physically diminished version of his previous self who is still running effectively by virtue of the cerebral traits that have always kept him in position to succeed on a carry-to-carry basis.