Speed Score 2020

After a one-year blip of poor performances, the running backs showed back up to the 2020 NFL combine.

Last year's running back class ended up disappointing in Indianapolis. The consensus top pick, Josh Jacobs, opted not to run. The big names that did run put up disappointing times. And, for the first time since 2014, no one topped a Speed Score of 115.0, as most of the backs ended up in much of a muchness. There was no Saquon Barkley to wow us, in other words.

This year, however, we had a pair of highly touted backs back up their hype on the track. For the first time since 2011, two different backs topped a 117.0 Speed Score. The duo of Wisconsin's Jonathan Taylor and Boston College's A.J. Dillon, two of the three heaviest backs at the combine, turned heads with their 40-yard dash times. With two of the 25 best Speed Scores we've ever recorded, Taylor and Dillon stole the spotlight in prime time.

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 4.5-second 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.

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

Did not run: J.K. Dobbins, Mike Warren

The Big Names

Jonathan Taylor's 4.39 was the fastest time among all running backs on Friday night.

Pure speed from Jonathan Taylor

4.41u 40-yard dash for the @BadgerFootball RB. @JayT23

: #NFLCombine on @NFLNetwork
: https://t.co/vDFxxNddNZ pic.twitter.com/O1NiTw7ybf

— NFL (@NFL) February 29, 2020

This would be impressive enough if Taylor wasn't a big guy. To do that at 226 pounds is exceptionally impressive, and his score puts him in appropriately rare air. Taylor's 121.7 ends up as the 10th-best score we've ever recorded.

Lance Zierlein compares Taylor to Ryan Matthews (with durability), and yeah, Speed Score can back that up. Back in 2010, Ryan Matthews ran a 4.37 at 218 pounds for a Speed Score of 119.6, very similar to Taylor's performance.

Taylor ran for at least 1,900 yards in all three years at Wisconsin, which is a plus and a minus -- that's a lot of wear and tear at a position which has a limited lifespan to begin with, but man, you can't deny that productivity. Taylor did a lot of that damage running into loaded fronts again and again and again, and that 40 time shows that he has breakaway speed when he has a chance to find some daylight. Taylor was considered a fairly solid Day 2 pick coming into the combine, and if anything, he might creep his way up. After all, since 2014, there have only been two running backs to weigh in at 225-plus pounds and still go under 4.45. Taylor is one. The other is Saquon Barkley. Taylor's no Barkley, mind you -- Barkley basically broke every single measurement the combine had to offer, while Taylor's non-40 numbers were more average. But that speed, at that size, with that history of production? Taylor made some money at the combine.

Seeing running backs weigh in at 225 pounds is rare, but not unheard of. That's why I'm almost more impressed by A.J. Dillon, despite his lower overall Speed Score. Dillon's 4.53 was just the 10th fastest among the 28 backs who ran at the combine, but he did that weighing in at 247 pounds. His Speed Score of 117.3 is the 22nd highest since electronic timing began, and the second best for a player weighing at least 240. People that large aren't supposed to move like this!

At 247 lbs, RB AJ Dillon (@BCFootball) runs a 4.53u 40-yard dash. @ajdillon7

: @NFLNetwork
: https://t.co/vDFxxNddNZ pic.twitter.com/LwNCaPNjes

— NFL (@NFL) February 29, 2020

Let's put that into context. There were 17 NFL running backs who clocked in at 240 pounds or more in 2019, per Pro Football Reference. Fifteen of them were fullbacks -- when you get that big, they ask you to stand in front of people and block, not tote the ball. Sixteen of them combined for 74 yards; the other was Derrick Henry.

Like Dillon, Derrick Henry weighed in at 247 pounds at his combine in 2016. He ran the 40 in 4.54, so Dillon was a hundredth of a second faster. There's your best-case comparison. But analysts are faster to compare Dillon to James Conner; they're concerned that he absorbs too much contact. They'd like him to drop weight and add quickness. I'm not sure how much more quickness you want to add to a 4.53, and that was far from his only impressive number. Dillon's 41-inch high jump led running backs, as did his 131-inch broad jump. He was near the top on the bench press, as well. Before the combine, there was some talk about Dillon maybe slipping into the second round; his stock has to be rising based on what we saw in Indianapolis.

Two other top names ran as well, though neither came within spitting distance of the top two. Georgia's D'Andre Swift had a very credible Speed Score of 105.3; he was the consensus top running back coming into the combine and didn't hurt himself at all with his performance. He'll be happy with the sixth-best Speed Score; he's not so much explosive as he is decisive and cerebral as a runner, so it's OK if he doesn't set the world on fire with his raw athletics. Very good is good enough.

Then you have Clyde Edwards-Helaire out of LSU. People were expecting him to run a sub-4.5 40, which would have been a very strong number. Instead, he fell down to a 4.6, in the bottom half of all running backs, much less Day 2 prospects. Edwards-Helaire did better in the drills and whatnot, so it's not like his combine was a disaster, but a 92.5 Speed Score is no good at all, and has him falling below the Arian Foster Line.

The Arian Foster Line

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

The Updated Speed Score track record, 1999-2015

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

Be big, be fast, or be Arian Foster. pic.twitter.com/tcL2CmgXI0

— Bryan Knowles (@BryKno) February 28, 2020

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 "1.3%" 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. That means that if Clyde Edwards-Helaire does develop into a 1,000-yard-a-year back, he'll be breaking new ground. That's not to say there have been no useful backs with poor Speed Scores; players like Andre Ellington and Dion Lewis had decent enough careers with sub-90 Speed Scores. That's just not the sort of player CEH was hoping to be compared to after the combine.

The other line is the Ahmad Bradshaw Line. Bradshaw had a terrible combine back in 2007, running a 4.61 40 and weighing in at 198 pounds. His Speed Score of 87.7 was a nightmare -- and yet, he still ended up a useful back. Only one player below that mark even managed 1,000 yards combined in their first five seasons, and most players at that level wash out after a year or two, if they're even drafted at all.

Three players this year fell below the Bradshaw Line -- Charlotte's Benny LeMay, Washington's Salvon Ahmed, and Arizona's J.J. Taylor. LeMay was always going to be a longshot to be drafted, but Ahmed and Taylor did tremendous damage to their stock with their inability to break the 4.6 barrier, despite both clocking in under 200 pounds.

Of course, the Bradshaw line might not be long for this world. One of the more disappointing combines last year went to Devin Singletary, who put up a 4.66 40 at 203 pounds, for a Speed Score of 86.1. And yet, he managed 775 yards as a rookie in Buffalo, thanks in large part to being a tackle-breaking machine. There's still a way to go before Singletary dethrones Bradshaw and becomes the new standard-bearer for solid performances from terrible combines, mind you, and Singletary wouldn't be the first sub-Bradshaw back to have a solid season or two and then vanish. Marcell Shipp twice had 800-yard seasons with the Cardinals, but still couldn't put together enough career yards to crack the chart above. But Singletary is a helpful reminder that a terrible combine day does not necessarily mean a terrible career is to come. Speed Score is correlated with success, but it's not fate.

Other Standout Performers

Three backs outside the top class had very solid Speed Scores. Florida State's Cam Akers, Appalachian State's Darrynton Evans, and Maryland's Anthony McFarland all hit 107.0 or higher, with all three running under 4.5 seconds at somewhere around 210 pounds. They represent three different tiers of runners, so they're good names to keep in mind if your team starts looking for a back late in the draft.

Of the three, it's Akers with the best prospects coming into the combine. He's not going to be a 200-carry bellcow or anything, but he put up solid performance for the Seminoles despite some terrible blocking ahead of him. He's not a bad option late on the second day of the draft; his 40 performance shows some potential burst that hasn't always been seen on the field.

McFarland is more of a Day 3 sort of back; something of a developmental prospect with a history of injuries and some unimpressive recent tape. He does have some splash performances on film, especially against Ohio State in 2018, so some teams are certainly interested. He may have earned himself a Day 2 callup with his combine performance.

Evans' performance might just have been enough to ensure that he's drafted at all. The smallest of the three, Evans is not going to become a great inside runner or a fantastic pass protector at the next level, but he's elusive and has solid hands and kickoff return experience. That alone would be enough to make teams consider him; a 4.41 40 might be enough to ensure they call his name on Day 3.