In Part I, we learned that there is a correlation between 40-yard dash times and wide receiver success in the NFL.

In Part II, we learned that there is a correlation between 40-yard dash times and where a wide receivers gets drafted.

Today: have NFL teams been properly evaluating 40-yard dash times when drafting wide receivers?

My plan *was* going to be as follows.  Let’s break things down into two buckets: wide receivers who were drafted much higher than their 40 time would indicate, and wide receivers who were drafted much lower than their 40 time would indicate. Then, see which category fared better. Should be easy, right?

On one hand, you have players like Larry Fitzgerald and Peter Warrick: wide receivers who were bringing something to the table besides their 40-time. Fitzgerald ran the 40 in 4.48 seconds yet was drafted 3rd overall. Warrick ran it in 4.58 seconds and was the 4th overall pick! Both players were dominant in college but not known for their speed: NFL executives certainly didn’t put too much weight in their 40 times when evaluating those guys. To the extent you think NFL teams always overweight the 40, Fitzgerald and Warrick are too good reminders that that is not the case.

The other group would contain players like say, T.Y. Hilton and T.J. Graham: wide receivers who were pretty clearly missing something.  For those who don’t remember the 2012 Draft, Hilton turned out to be the best wide receiver, but we didn’t know it at the time. Despite a blazing 4.34 40, Hilton was the 13th wide receiver selected that year.  Meanwhile, Graham also ran a 4.34 and was the 11th wide receiver taken in that same draft; the former North Carolina State product never materialized into a star wideout either in Buffalo or elsewhere during his time in the NFL.  Two wide receivers, same 40 time, same draft, both drafted late…. and two very different careers.

You might be wondering why I am not using a pair of first round wide receivers for the Hilton/Graham bucket. That’s because nobody, based on 40-time alone, is expected to be a first round pick. That’s an important thing to keep in mind and the first hint that my plan was going to hit some snags.  Consider: there were 17 wide receivers who ran the 40 in under 4.30 seconds from 2000 to 2017; Kent State’s Dri Archer was taken with the 97th overall pick, making him the median draft player in that group (i.e., 8 of the 17 wide receivers were selected later than Archer, and 8 earlier). Nobody, just based on a fast 40 time, is expected to be a first round pick; it was only six years ago when JJ Nelson ran a 4.28 40 and wasn’t selected until the 159th pick in the Draft. Tiquan Underwood ran a 4.31 40 and was the 253rd pick! Suffice it to say, the 40 is just a small part of the prospect profile, and that’s going to be the most important lesson you learn today.

Now, we know there is not a strong correlation between the 40-yard dash and draft status. After all, it is just one of many variables, even if there is some correlation. But my question is still out there: do the Fitzgerald/Warrick wide receivers turn out to be better pros than the Hilton/Graham types?

Unfortunately, that’s a tough one to answer.

Linear Regression

A linear regression analysis is a simple starting point to set expectations. I looked at all wide receivers drafted in the top 200 from 2000 to 2017. If we perform a regression using “Football Perspective Draft Value” as the sole input and “receiving yards gained in their first four seasons” as the output, we find a strong correlation between the two variables. The R^2 is 0.31, and there is no question that the connection is statistically significant. ^[1]In this case, a P-value of 6.74639E-36. The best-fit formula to predict receiving yards through four seasons is 326 yards + 120.5 x FP Draft Value. So a WR that gets drafted first overall (FP value of 34.6) would be expected to have 4,495 yards through four years. A WR drafted 10th overall (FP value of 19.9) would be expected to gain 2,724 yards through four years, and a WR drafted 80th overall (6.7) would only be expected to gain 1,133 yards. ^[2]That is not a bad guess: from 2000 to 2017, wide receivers drafted between picks 70 and 90 gained an average of 1,195 yards during their first four seasons.

Okay, this level sets some expectations: receivers drafted earlier gain more yards.  Now, what happens if we also include a player’s 40-yard dash time? The R^2 changes to 0.32 with almost all of the connection still driven by draft value. That said, what about the 40-time variable? It might actually be statistically significant (P-value of 0.03), but it isn’t practically significant; the coefficient is 1210, which means for every 1 second of 40-yard dash time, a prospect’s expected yardage total through four years — after accounting for draft position — would increase by 1,210 yards. But in the windows we are looking for, we are more interested in tenths of a second, and this means you would project an extra 121 receiving yards over four years for every tenth of a second in 40 time. That’s 30 yards per year of a chance if a guy runs a 4.4 instead of a 4.5.  In other words, the significant may be significant statistically, but not practically.

The fact that the relationship is positive and not negative is the most meaningful part of the conclusion. This is hardly strong evidence that 40 time is important, but I would use this as evidence that 40 time is not being OVER-valued by NFL teams. If anything, the evidence here suggests that teams are (ever so) slightly undervaluing 40-yard dash times. In other words, while I wouldn’t attach  practical significant to the p-value, I do think this is decent evidence to reject the hypothesis that NFL teams overdraft wide receivers based on 40 time.

Can We Look At Players Who Overperformed?

Next, I looked at all wide receivers drafted in the top 200 from 2000 to 2017. I wanted to use the top 200 criteria to filter out low-graded prospects. There were 422 wide receivers who met this criteria. I thought it would be interesting to look at the biggest overperformers and see whether or not they had slow or fast 40 times relative to their draft position.

One problem quickly emerged. There isn’t much of a correlation between draft status and 40-yard dash time once you remove players drafted outside of the top 200. It’s still there, but less significant and practically almost meaningless. Consider: the difference in expected 40 time between a wide receiver drafted in the first round isn’t much different than the expected 40 time of a wide receiver drafted in the fourth round. The graph below shows Football Perspective Draft Value on the X-Axis, and 40-yard dash time on the Y-Axis, for these receivers.

In short, wide receivers drafted in the early rounds have very similar 40 times to wide receivers drafted in later rounds, which makes it particularly hard to study whether or not 40 times are overrated. They don’t seem to be “rated” very much at all.

It’s hard to figure out if a wide receiver “fell” or “rose” because of his 40 time, because we are dealing with such small movements. If a receiver runs a 4.50 instead of a 4.55, might he get drafted a little earlier? Sure…. but that would be the same for any other criteria. A receiver who caught two more touchdowns, or interviews slightly better, or stayed a little healthier would also get drafted earlier. A 2nd round wide receiver running .02 seconds faster than a 6th round wide receiver is practically meaningless.

But What About The Big Overachievers?

The top six wide receivers statistically during this period were Michael Thomas, A.J. Green, Anquan Boldin, Mike Evans, Larry Fitzgerald, and DeAndre Hopkins. None of them had a fast 40 time, with each running the dash in 4.57, 4.48, 4.72, 4.53, 4.48, and 4.57 seconds, respectively. So is this evidence that the 40 is overrated?

Not really. It’s evidence that the 40 isn’t that important, not that it’s overrated. Four of those players were first round picks; Thomas and Boldin were second round picks, but not solely (or even largely) because of their 40 time. The fact that these players were highly drafted despite poor 40 times (lower than the average 6th round pick!) is evidence that GMs are not placing too much emphasis on the 40-yard dash, just like Hilton isn’t evidence that GMs are placing too little. Did GMs not care enough about the 40 yard dash when Green went just ahead of Julio Jones (4.34) in the 2011 Draft? I don’t think so.

Yes, on the margins, really fast wide receivers will get drafted much earlier than really slow ones. There is a correlation between 40 time and draft status, although that may not necessarily be a causal relationship (I suspect there’s a correlation between 40 time and college program, too). But I don’t evidence that NFL decision makers tip the scale to any significant degree when it comes to wide receivers and 40 times.