The speed of light.

Have you ever thought about whether or not those lasers you see in movies are real? When an intruder walks in the path of a laser, do alarms really go off? Do they actually fall through a trap door? The simple answer is yes, these lasers are real. Their application and how they are used in real life is usually different from the way they are used in movies, but they are real!

LASER stands for Light Amplification by Stimulated Emission of Radiation (Rouse, 2018). Essentially, it is a concentrated beam of light made up of atoms in an excited state...yawn. You're probably wondering what this has to do with sports? Maybe when Tom Brady throws a touchdown pass people say 'that pass was like a laser', or when Cristiano Ronaldo scores a free from 40 yards out, it was 'like a laser into the top corner'. The actual use for lasers in sports is far more technical than that though, which I will now explain.

We can see the use of lasers in everyday life such as barcode scanners or X-rays. They have become an essential part of how technology is used in our everyday lives, and they are becoming increasingly useful in sport. In sport, lasers are often used to measure the speed of an athlete over a certain distance. The lasers are placed opposite each other at a start line and a finish line. The difference in time between when they break the first laser beam and when they break the second beam gives an accurate and consistent indication of how long it took the athlete, and therefore how fast they are over that distance. These lasers placed opposite each other are widely referred to as 'light gates'.

A prime example of the use of light gates in sport is in the NFL Scouting Combine. The combine is an annual event where college football's best talents gather to shows off their athleticism and skill. It is a hugely popular event, with the 2013 combine amassing a viewership of 7.35 million people. The majority of those people are only watching to see one event, the 40-yard dash, which is a straight line sprint over a 40-metre distance. It is the highlight of the combine and it has been given numerous nicknames such as the 'dash for cash' (Davenport, 2013).

The fastest 40-yard dash versus the fastest man alive.

The difference between a record-breaking 40-yard dash and an average 40-yard dash comes down to milliseconds. For an event this popular and important in the world of professional sport, these milliseconds can mean everything to an athlete. They could be the difference between signing an NFL contract or not. Technologies like light gates allow for the accurate measurement of these athlete's speed.

Historically, hand-held stopwatches were used for measuring the 40-yard dash. Fully Automated Timing (FAT) is the type of technology that uses light gates at the start line, the finish line and numerous others distances in between (usually the 10, 20 and 30 metre marks) in order to measure times accurately. The result of using FAT to measure the time of a 40-yard dash will almost always be more accurate than timing by hand. FAT times will usually be slower than times done by hand as well because there is a human delay in starting the timer. Humans tend to start the time after the athlete starts running rather than when exactly they start. Studies have shown that the delay between timing the 40-yard dash by hand and by electronic methods such as FAT is between 0.10 and 0.25 seconds (Weinstein, 2018). This may not seem huge at first, but when you consider that the difference in time between the fastest and second fast 40-yard dashes recorded is 0.02 seconds, this delay seems much bigger all of a sudden. When the athletes being measured are as fast as lightning (excuse the pun), it is important to be as accurate as possible. The main advantage of FAT is its consistency. Times measured by hand can vary depending on numerous factors, but light gates are extremely consistent for the most part which makes them the obvious method of choice when measuring the 40-yard dash.

Top five 40-yards dashes since 2006 (Haislop, 2020)

Despite the accuracy of FAT, the current method of measuring the 40-yard dash doesn't actually use it; it only uses partially automated timing. This means that the start is measured by hand, but the remaining distances including the finish line are measured electronically by lasers to give an 'unofficial' time. This unofficial time is then adjusted to compensate for the delay made by the hand measurement at the start to give the official time. FAT times aren't used because their times are expected to be considerably slower which could bother the athletes (Davenport, 2013). This makes the 40-yard dash a subjective exercise because the times aren't completely accurate, but hey, one light gate is better than none isn't it?

Aside from American Football, light gates have become popular in other sports too, be it tennis or soccer. Both individual and team sports use light gates to keep athletes accountable. Similar to the use of GPS, light gates allow for the consistent measurement of the progress of athletes. For example, light gates can be used in fitness and speed tests at the start of the sporting year. These tests can then be done again in a couple of weeks time to see the progress the athlete has made. New technologies like light gates mean there really is no hiding for athletes these days, as everything is tracked down to the millisecond or millimeter. How fast do you think it would take you to do the 40-yard dash? Let us know in the comments below!

An athlete at the NFL combine, running through numerous sets of light gates.

References

[1] Davenport., G, 2013. Bleacher Report – How are 40-yard dash time recorded? [online] Available at: <https://bleacherreport.com/articles/1543670-how-are-40-yard-dash-times-recorded> [Accessed 24 March 2020]

[2] Haislop., T, 2020. Sporting News - NFL Combine records: Top 40 times, bench press reps, more. [online] Available at: <https://www.sportingnews.com/us/nfl/news/nfl-combine-records-40-yard-dash-time-bench-press-cone-drills/s4irh4fm14k31ok9e4ijkglnl> [Accessed 24 March 2020]

[3] Rouse., M, 2018. WhatIs.com – Definition of a laser. [online] Available at: <https://whatis.techtarget.com/definition/laser> [Accessed 24 March 2020].

[4] Weinstein., M, 2018. Zybek Sports – Hand-times versus electronic-timed 40 yard dash. [online] Available at: <https://www.zybeksports.com/hand-timed-versus-electronic-timed-40-yard-dash/> [Accessed 24 March 2020]