Every year, prospects who performed well in athletic testing at the NFL Combine will soar up draft boards in the two months leading up to the Draft. The most noticeable, daily reminder of this phenomenon for me is my Twitter timeline, where it’s impossible to escape GIFs of Notre Dame WR Chase Claypool running a blazing 4.42 or Anthony McFarland running a 4.45. As I sat on my couch watching these incredible feats of athleticism, a question came to mind: to what extent is Combine performance correlated with NFL success?
Faced with an overwhelming amount of data, I decided to narrow the scope of this question to include just offensive skill position players. Although strong combine performances benefit players of all positions, the biggest post-Combine risers always seem to be RBs, WRs, and TEs. The benefit of examining these three positions is that their success in the NFL is easier to quantify with statistics.Before I actually answer the question of whether good Combine performances are correlated with NFL success, it’s worth asking why there’s so much overemphasis on the NFL Combine for skill position players.
The beauty of the Combine is that it is an accessible, low-commitment way for fans to engage with the Draft process; however, this often leads to it being the only way fans get involved in the Draft process. While front offices view Combine testing as a valuable supplement to film scouting, many fans view it as their primary evaluation tool.
As a result, it is important for fans to understand the extent to which strong performances in certain drills correlate with success in the NFL. To answer this question, I compiled data tables on the top 15 Running Backs, Wide Receivers, and Tight Ends in the NFL based on data from mockdraftable.com. One can quibble with how I determined the top-15 for each position group, but I ultimately decided that the top-15 Running backs would be based on average rushing yards per game last season and the top-15 receivers and tight ends would be based on receiving yards per game last season. I understand, and am sympathetic to the argument, that there are other valid ways of determining the top-15 players at each position than using the two statistical categories I employed, and that using different metrics would lead to different player rankings. However, I believe that rushing and receiving yards per game are the two most revealing metrics for these positions and, more importantly, the central conclusion of this article would not change even if I had used different metrics.
For those interested in accessing the raw data I’ve compiled, you can click here.Across all three positions, only one metric was consistently correlated with NFL success: speed score. Speed score, invented by Bill Barnwell of Football Outsiders, is a way of tying a player’s 40 time to their weight. The equation for speed score is (200 x <weight>) / ( <40 time> ^ 4).
A speed score of 100 represents the average speed score for NFL-quality RBs. Speed score is incredibly useful because it provides proper context for times that may seem unimpressive on the surface. For example, Derrick Henry ran a 4.54 40 yard dash, which is only slightly better than the Combine average of 4.56, but Henry’s speed score is 116.3. Saquon Barkley was the only top-15 RB with a higher speed score (124.3).
As you can see in the data table, the top-15 RBs averaged a speed score 6 points higher than the Combine average. The top-15 WRs averaged a speed score 5 points higher than the Combine average, while the top-15 TEs averaged a speed score a whopping 15 points higher than the Combine average. Interestingly, the 40 yard dash times for top-15 RBs and WRs were nearly identical to League average. Thus, while the 40 yard dash is not correlated with success in the NFL for RBs and WRs, speed score is. This is a perfect segué to this study’s second biggest takeaway: athletic TE’s are successful TEs.
While Speed Score was the only metric that differentiated the top-15 RBs and WRs from the rest of the League, the top-15 TEs consistently dominated every single Combine event with the exception of the Bench Press. Top-15 TEs, on average, ran .05 seconds faster in the 10 yard split, jumped 5” more in the broad jump, 2” more in the vertical jump, a whopping .17 seconds faster in the 3 cone, and .09 seconds faster in the 20 yard shuttle. That being said, while athleticism seems to be a prerequisite for TEs to succeed in most NFL offenses, athleticism is not the only thing that matters. In fact, there are many athletic TEs who don’t have great careers in the NFL. This leads me to my third and final takeaway.The reason players succeed in the NFL is not because of athleticism, but rather technical prowess. In fact, some of the top Offensive skill position players in the League have succeeded in spite of their athletic abilities. Devin Singletary (RB, FAU) averaged over 5.1 yards per carry as a rookie, despite an 86 speed score, because of his incredible vision and slipperiness: neither of which can be quantified by Combine tests. Keenan Allen (WR, CAL) has been a consistent 1,000 yard receiver, even though he ran a 4.71 40 time at his pro day, because of his diverse release packages and nuanced route running. And Mark Andrews, despite testing below the 50th percentile in every Combine event except for the 40 yard dash, has become one of the best young TEs in the NFL because of his knack for finding open space and subtly getting behind defenders.
Testing is not everything, and a myopic focus on athletic testing in the Draft leads to teams drafting athletes, not ball players.
As a football fan, I totally understand the fascination with athletic testing and I, like every other fan, love to watch skill position players run the 40. However, as fans, I would argue that we have the responsibility to not be hostages of recency bias and actively seek to evaluate players not just based on how well they run in underpants, but based on how well they played against premier competition. Hopefully, this article provided some useful context for what you saw this weekend!