Metrics that Matter: Learning from weight-adjusted 40 times

At the 2017 NFL Scouting Combine, eventual No. 4 overall pick Leonard Fournette ran a 4.51-second 40-yard-dash. San Diego State running back Donnel Pumphrey ran a 4.48. Who had the better 40 time?

Pumphrey technically ran a “faster” 40 than Fournette, but he did not run a “better” 40. What do I mean by this? Fournette weighed in at a whopping 240 pounds at the Combine – 64 pounds heavier than Pumphrey. When factoring in weight, Fournette finished 0.23 seconds better than expected, while Pumphrey was 0.13 seconds slower than expected.

When looking at college prospects, I spend hours looking at tape, looking at statistical production, and then, finally, looking at athletic measurables. My favorite catch-all combine stat is the weight-adjusted 40-yard-dash (or Speed Score.) The formula for this is: (Weight*200)/(40-yard-dash^4). It’s not a perfect stat by any means, and athletic measurables factor much less into my rankings than production, but it is a fun one.

Looking at combine data since 2000, here are some notable names who jump out at each position.

Weight-adjusted 40-yard-dash times

Quarterbacks: Among all 326 quarterbacks to run the 40 at the combine since 2000, Tom Brady has the second-worst weight-adjusted 40 time. Robert Griffin III ranks first, followed by Michael Vick, and then Cam Newton. Colin Kaepernick ranks sixth-best. Marcus Mariota 11th. Andrew Luck 13th.

Running backs: Due to off-the-field concerns, Joe Mixon was not invited to the combine. He ran a 4.50 40 at his pro day, while weighing in at 228 pounds. If we lump this in with all other running backs to participate at the combine this year, he would have ranked second-best — just behind Fournette (37th-best since 2000) and just ahead of Joe Williams.

Wide receivers: In 2011, Terrelle Pryor ran a 4.38 40 at his pro day. He weighed in at 232 pounds. If we take his pro day numbers and compare them to all wide receivers to run at the combine this past decade, his weight-adjusted 40 time would have ranked fourth-best among wide receivers.

Although Darrius Heyward-Bey has had a fairly disappointing NFL career, it’s hard not to get excited when you see the first two names on the list. Some other notable names ranked highly as well. Andre Johnson and Vincent Jackson both posted weight-adjusted 40 times over 120 at their respective combines.

Pryor wasn’t very efficient on a per-target basis last season, but he did reach the 1,000-yard mark while catching passes from Cody Kessler, Josh McCown, Robert Griffin III, Charlie Whitehurst, and Kevin Hogan. Oh, and as a converted quarterback, he had just two career NFL receptions prior to 2016.

Tight ends: Since 2000, rookies for 2017 Evan Engram and O.J. Howard both rank top-10 among tight ends in weight-adjusted 40 time.

There are certainly some encouraging names on this list. Greg Olsen finished third-best among fantasy tight ends last season. Ben Watson finished seventh-best two seasons ago. Vernon Davis has multiple seasons in the top two. Ladarius Green ranked behind only Rob Gronkowski in yards per route run last season. And we all know of Jimmy Graham’s dominance at the position.