Jonathan Taylor and A.J. Dillon Are Rare Size-Speed Specimens: 2020 RB Speed Scores
Image Credit: Lee Coleman/Icon Sportswire. Pictured: Cam Akers.

C.J. Spiller ran the forty-yard dash in 4.27 seconds at the 2010 NFL combine. This is one of the fastest times ever recorded. Spiller weighed 196 pounds when he achieved this feat. Fast forward to the 2020 combine, in which Jonathan Taylor ran the forty in 4.39 seconds, and one may ask which time is better. Although not as fast as Spiller’s, Taylor’s time might be more impressive. Why? Because he weighed 30 pounds more than Spiller when recording it. Naturally, it’s alluring when a large RB prospect can keep up with his more streamlined counterparts.

In 2008, Football Outsiders created an equation to help us compare the forty times posted by RBs of various sizes in what they called “Speed Score.” The equation is straightforward and calculated by multiplying a back’s weight by 200 and dividing this result by his forty time set to the fourth power.1

While impressive, Spiller’s speed score of 118 falls short of Taylor’s 122. In fact, using a data set that goes back to 2000, only eight RBs have done better. Keith Marshall posted an absurd speed score of 127 in 2016 by running the forty in 4.31 seconds at a weight of 219 pounds. Mario Fannin, a 2011 prospect, posted a time of 4.37 seconds while weighing in at 231 pounds, good for a speed score of 127. Saquon Barkley ties with Knile Davis, Ben Tate, and Brandon Jacobs who recorded scores of 124 and Kevin Jones and Andre Brown managed 123.

As highlighted by these names, a strong speed score doesn’t guarantee success. It does, however, give us a way in which can compare the mixture of size/speed that RB prospects possess. The 2020 class placed just two backs in the 90th percentile; Taylor and A.J. Dillon.

2020 RB Speed Scores and Historical Percentiles2

 
Name Height Weight Forty Speed Score Percentile
Jonathan Taylor 70 226 4.39 122 98%
A.J. Dillon 72 247 4.53 117 96%
Cam Akers 70 217 4.47 109 84%
Darrynton Evans 70 203 4.41 107 82%
Anthony McFarland 68 208 4.44 107 80%
D’Andre Swift 68 212 4.48 105 75%
Joshua Kelley 71 212 4.49 104 72%
Ke’Shawn Vaughn 70 214 4.51 103 69%
Rico Dowdle 71 213 4.54 100 57%
Patrick Taylor 73 217 4.57 100 53%
DeeJay Dallas 70 217 4.58 99 50%
Raymond Calais 68 188 4.42 99 49%
Sewo Olonilua 75 232 4.66 98 49%
Scottie Phillips 68 209 4.56 97 43%
JaMycal Hasty 68 205 4.55 96 39%
Zack Moss 69 223 4.65 95 38%
Eno Benjamin 69 207 4.57 95 35%
Lamical Perine 71 216 4.62 95 34%
James Robinson 69 219 4.64 94 33%
LeVante Bellamy 69 192 4.5 94 30%
Clyde Edwards-Helaire 67 207 4.6 92 27%
Jet Anderson 70 208 4.61 92 26%
Javon Leake 72 215 4.65 92 25%
Brian Herrien 71 209 4.62 92 24%
Tony Jones 70 220 4.68 92 23%
Benny LeMay 68 221 4.75 87 11%
Salvon Ahmed 71 197 4.62 86 10%
J.J. Taylor 65 185 4.61 82 2%

Forty Time versus Weight

The scatter plot illustrates how, for the most part, forty times increase as player weight increases. However, there are players such as Cam Akers, Taylor, and Dillon that manage to plot in the lower half of the scatter and toward the right. If you’re looking for size/speed specimens, this is where you’d want to focus.

As shown, Taylor and Dillon truly separated themselves from the pack. Speed score is an important metric for the position and as a result, Taylor surely augmented his case for being the 2020 RB1 and Dillon proved that his high marks in the RB Prospect Lab are justified.

  1. weight*200)/(forty time^4  (back)
  2. Based on Combine results dating back to 2000.  (back)

Dave Caban

Senior Fantasy Analyst, app developer, hosts the RotoViz Radio Flagship, auction draft enthusiast.
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