Deneric Prince, Jahmyr Gibbs Lead 2023 Speed Scores

NFL Draft - Fewer running backs than usual ran at this year's scouting combine—only 15 took the field to have their 40-yard dash officially recorded. We had 27 a year ago, and the only other occasion with fewer than 20 entries in our database was back in 2003, the beginning of official combine data. Injuries and reluctance thinned the field somewhat, meaning we have fewer backs than normal to talk about in terms of Speed Score. Most of the backs who did run avoided making too much of a mess of things, though there are a couple players who may have slid from Day 2 to Day 3 after appearing more sluggish than advertised. Let's get into the details!

Created by Bill Barnwell and introduced in Pro Football Prospectus and ESPN Insider back in 2008, Speed Score is one of Football Outsiders' metrics for evaluating running back prospects. It's built on the simple idea that smaller backs tend to run faster than larger backs, so we should be more impressed by a 4.5s 40-yard dash from a 220-pound back than the same clock reading from a 170-pound back. As such, Speed Score incorporates a back's official time in the 40-yard dash with his weight to produce a measure of his speed given his size using this formula:

(Weight * 200)/(40 time^4)

The average running back who makes it to the NFL will have a Speed Score around 100.0, with most prospects at the position falling between 85.0 and 110.0.

Speed Score measures speed in the context of strength and power. It doesn't measure agility, receiving ability, or any of the other aspects related to the position. It does not claim that a larger player with a higher 40 time is somehow faster than a smaller player with a lower 40 time thanks to the power of exponentiation. Speed Score is useful because it's beneficial for a running back to be both fast and large.

Speed Score has a higher correlation with yards, carries, and DYAR than 40-yard times alone, making it a better way to contextualize the performances at the Underwear Olympics and a better tool for finding valuable players later in the draft. It's also a part of our BackCAST projections, which combine these numbers with college production and will come out later this offseason.

Last year, your Speed Score leaders were Isiah Pacheco (118.5), Breece Hall (116.9), and Kenny Walker (114.7). Pacheco and Walker ended up with Offensive Rookie of the Year votes, and Hall was well on his way to doing the same before his midseason injury—not a bad list of players to have in your top three. There were no Pachecos or Halls this year, though; no one really shattering any records on their way to the top.

Let's start with the Speed Score table, and then discuss the notable names and numbers on it.

Did not run: Israel Abanikanda, Travis Dye, Zach Evans, Eric Gray, Mohamed Ibrahim, Hunter Luepke, DeWayne McBride, Kendre Miller, Chris Rodriguez, Tyjae Spears, Sean Tucker, Deuce Vaughn

Top Performers

Breaking a Speed Score of 110.0 is an important milestone; it gets you into some rarified air. Only 81 of the 620 running backs to do a 40-yard dash at the combine since they went to electronic timing in 1999 have hit 110.0, and about 35% of them have gone on to have successful NFL careers. That doesn't sound like a huge number, but only 14% of all running backs to show up at the combine manage 2,500 yards in their first five seasons, so we're talking being two or three times as likely to succeed once you enter this sort of range.

Your Speed Score winner this year is Tulsa's Deneric Prince, with a 118.5 (4.37 at 216 pounds)

Deneric Prince 4.41u#NFLCombine2023 pic.twitter.com/pbMQlL0zpE

— WalkTheMock (@WalkTheMock) March 5, 2023

Prince may have just run himself into a job. Before the combine, the NFL's scouting reports called him a candidate for the bottom of a roster or the practice squad. They praised his size and power but questioned his vision and said he had a below-average burst. A 4.41s 40 doesn't exactly scream "below average," especially for a six-foot-tall bowling ball such as Prince. Prince also scored highly on some of the other athletic drills, hitting a broad jump of 10-foot-4. At his size, those are some off-the-charts athletic numbers. Don't expect him to become this year's Pacheco and threaten the top of the rookie leaderboards or anything in 2023; Prince topped out at 729 yards as a senior for Tulsa. But he's hard to bring down when he gets a full head of steam going, and Sunday's performance is going to get people to go back and give him a second look. This builds off of a solid if not standout Shrine Bowl performance; he's certainly trending upwards through the process. It might be the difference between hearing his name called in April and wading through the UDFA waters, and from there, who knows? Bowling balls still have a role to play in the NFL; Prince could carve himself out a solid career as a power back if he can translate these numbers into on-field production.

But if Prince is trying to play himself into the draft, the man he finished just ahead of is trying to play himself into the first round.

Alabama's Jahmyr Gibbs is the consensus second back on the draft board behind Texas' Bijan Robinson. At the combine, however, Gibbs was a full tenth of a second faster than Robinson, finishing second behind Devon Achane by running a 4.36. That's a great number for Gibbs, who is going to live and die by his speed and hands. At under 200 pounds, he's not a between-the-tackles runner. Instead, he wants to be the next Alvin Kamara or Christian McCaffrey, widening the field and being a mismatch in the passing game. Well, McCaffrey and Kamara had OK Speed Scores—100.3 and 99.0, respectively. Those were solid results, and their performance in drills and the passing game was enough to get them drafted relatively highly. Gibbs clocks in at 110.1, significantly above either of his self-chosen comparisons. His size is still a concern; only a dozen backs under 200 pounds have had 150 touches since 2017. That might keep Gibbs away from bell-cow status, but his ability to take the ball to the house anytime he touches it should be catnip to the more creative offensive coordinators in the league. Maybe he does sneak into the back of the first round for an Andy Reid type and becomes the NFL's next matchup nightmare.

The Arian Foster and Ahmad Bradshaw Devin Singletary Lines

Speed Score doesn't guarantee anything, of course, but the higher your score, the better the career you generally have. You can see the production of backs fall off as Speed Score drops off in this table:

Just getting ready for tomorrow's running back action...

Speed Score table! X% of players with a Speed Score of Y go on to average Z yards per season.

In short: Run really fast, be really big, or be Arian Foster. pic.twitter.com/zv1riEb8OJ

— Bryan Knowles (@BryKno) March 4, 2023

One of the better uses of Speed Score, I think, is as a negative indicator. You can run fast and still not succeed at actually playing football; you may be a track star in pads. But if you can't run well in jockey shorts, the odds that you'll transition into a successful running back in the pros drop dramatically.

There are a pair of "lines" we like to track—floors for production. Arian Foster is one of them; he had a Speed Score of just 94.2, but still topped 5,000 yards in his first five years. He's the "1.1%" on the chart—the only running back with a Speed Score under 100.0 who managed to average a thousand yards a season for five years. He's the only player since electronic timing was introduced to have a below-average Speed Score and still develop into a superstar. Only five backs ended up below the Foster line, and most of them were borderline prospects anyway. It sort of confirmed Tavion Thomas and SaRoderick Thompson as undraftable prospects; they needed to do something special and turn heads just to get picked in April, and they didn't do that.

The other line we have historically tracked is the Ahmad Bradshaw Line. Bradshaw had a Speed Score of 87.7 back in 2007. Until recently, he was the lowest-scoring back to hit 2,500 rushing yards in his first five seasons, and one of only two to hit 1,000. But we're going to have to slide that line down a tad because Devin Singletary has already hit those marks. Singletary's Speed Score of 86.1 (a 4.66s 40 at 203 pounds) was part of a terrible day at the combine in all the drills. He's now the shining light in the darkness; the hope for players with awful days that they can still make an impact in the NFL. The point stands, however—if you're being compared to the Bradshaws and Singletarys of the world, your chances of a successful NFL career rapidly approach zero.

Only Thompson fell below the Singletary line this year, and he was already a borderline candidate. Instead, the worst performance by a player who may be be drafted goes to Georgia's Kenny McIntosh. There were already concerns about his elusiveness and vision, and now he was downright slow—a 4.62s 40 at 204 pounds is just not going to cut it. Maybe it gets him a job with the Rams—Los Angeles used both Ronnie Rivers and Kyren Williams last season, both of whom were under 200 pounds and a 40 of 4.6X seconds. These aren't the kind of names McIntosh was hoping to be compared to, however; he was trying to crack Day 2 and the top 100 picks, but his stock is going to drop down significantly after his run.

Other Big Prospects and Standout Performances

Bijan Robinson didn't get headlines in the 40, but he doesn't need them. He didn't quite crack the 110.0 barrier, but his Speed Score of 108.7 is certainly not going to scare anyone away. It would have been great to see him be a tad faster, but there was some talk before the combine that he was just hoping to beat a 4.5, so a 4.46 is more than fine. Robinson's athletic numbers don't quite match his production on the field, but that's just because he had insane production numbers. He would have had to have a truly disastrous combine to hurt his stock, so he'll take his 40 to the bank.

Texas A&M's Devon Achane had the quickest 40 at 4.32 seconds; he's just 188 pounds but is fast enough that he likely secured his status as a second-day pick despite his small stature. It's also worth keeping an eye on Northwestern's Evan Hull, who turned some heads with an unexpected 4.47 and a Speed Score of 104.7; he was projected as a UDFA, but that speed coupled with his route-running skills may be worth a second look.

Really, the theme of the day was fine performances; most players didn't hurt their status much in the 40. Illinois' Chase Brown and Louisville's Tiyon Evans are projected Day 3 picks and both put up good Speed Scores—probably not good enough to knock them into Day 2, but it should make sure they do in fact get drafted. UCLA's Zach Charbonnet would have liked to run a sub-4.5 40, but his average acceleration was already more-or-less priced in to his projection as the third-best back in the draft; his size, blocking ability, and pass-catching skills are his main selling points, and an average 40 isn't going to destroy him.

It's more interesting that so few players ran the 40. Some people had injury reasonings—DeWayne McBride wasn't going to touch the field as he recovers from an injured hamstring, for example—but Eric Gray, Mo Ibrahim, Tyjae Spears, and Deuce Vaughn were doing the other drills, just not taking part in the 40. We'll have to wait and see if this is a one-year blip, or if skipping the 40 at the combine starts being a regular occurrence.