Some of us readers have been discussing, how the unofficial and official 40 yard times actually are measured and why there is such a huge span between those two times. I did some diggin' and here is what I found.
This* article describes the unofficial and official times as:
Since 1999, the NFL has used partially electronic timing to determine 40-yard times at the combine. The start of the run is timed by hand, but the finish is recorded electronically using a laser "plane" that runs across the finish line.
That "unofficial" time is then adjusted (presumably to compensate for the reaction time of the hand-timed start), and the "official" combine time that the media and fans drool over is then determined.
This means that my first explanation of these two different times were wrong. It also blurs the actual method the NFLN uses to come up with the official time**.
- Those who participate in the 40 actually run twice, and on each run they are timed by two hand-held stopwatches and one electronic timer (that is actually initiated by hand on the player's first movement).
- Combine data put together for NFL teams by National Scouting includes all six of those times for each player, but no single official time.
Team scouts and coaches have various approaches for reaching agreement on a 40 time they use from those six timings. Some use averages. Some throw out slowest and fastest and then average the rest. Some ignore the whole thing and use a time taken by their own scout.
So how does the different methods of timing the athletes correlate to each other? I found this article which pretty much sums it up:
1- Electronic start - electronic finish. This should be the standard but, unfortunately is not. The start is done with a touch pad and the finish with a photocell. This is the most accurate and as a result yields the slowest times. An electronic start/ electronic finish time has been shown to be .22 seconds slower than a hand held 40 yard dash. ( Brown, 2004)
2- Hand Start - electronic finish. This is a system used uniquely at the NFL Combine. A hand start-electronic finish will be approximately .1 seconds slower than a hand held 40 yard dash. In the combine the use of hand start will be particularly evident in the faster ten yard dash times. Athletes will run 10 yard times much closer to a hand held but, times at each following split will be closer to the electronic time.
3- Hand Start - hand finish. this is the fastest and least accurate. Handheld times tend to be faster but are clearly more prone to human error. Many of the legendary times I believe were hand-held timing combined with human error or human expectation.
Later in this article, he tries to compare Ben Johnson's and Carl Lewis's split times (40 meters) in their 100 meters run on track, using blocks. He does it wrong, as he forgets to count for the reaction time these two sprinters have in these runs, which does not include in the 40 yard dash. With that out of the way...
Then you might ask, and as do I, why won't the NFL change their way of timing the athletes to a electronic start - electronic finish? Well, they tried it at the 2012 combine. According to Rob Rang's report, here is why that failed:
According to coaches and scouts who discussed this with The Sports Xchange, the FAT (red. Fully Automated Timing = Electronic start - electronic finish) times are expected to be .20 to .24 seconds slower than the relative times recorded using methods the Combine has gone with since 1990, and before.
"We were told it is just an experiment and we won't be told the results," said one team official. "People are worried about the reaction players may have if the 40 times change that much."
There it is. The power of traditions and fear of changing them, is holding the NFL back. The final question could be, is the unofficial or official time the most accurate? My answer is neither. As our statistic guru Uppercut replied to me in our discussion:
In 2010 (the example I like to go to), Taylor Mays had a sub 4.3 "unofficial" 40 and I think Trindon Holliday had about 4.30. When the "official" times came out, Holliday had 4.34 & Mays 4.43 (checked those on NFL.com just now), and yet when they played the overlayed/simultaneous clips of the runs, Mays beat Holliday. Rich & the guys were surprised & talked about it a while….but nothing came of it from there. (no changes, etc)
Even when the NFL tries to compensate for their hand-timed starts (in a mysterious way), the results come out very wrong. Trindon Holliday even holds the record of the 40 at the Combine if you ask NFLDraftScout.com (Bleacher Report article) with his 4.21. This does not make any sense, if Mays beat him if you overlay the runs.
My conclusion: Next time you see these 40 yard times, don't put too much into them, because their inaccuracy has been known for years.
* Yes, it is Bleacher Report, but this correlates with other found data and makes sense.
** I have not found any data which answers this question in my research.
PS. This one got a little longer than expected, and this is my first FanPost, so please be give constructive critique (I know my commas and other grammar are bad. It's even bad in Danish!). Hej mor!