Blink and you’ll miss it
The next question in our Ask a sports engineer series is: Are sports getting too fast to view?
With the constant pushing of boundaries by athlete’s and the wider availability of sports scientists and top coaches many sporting events are becoming more and more closely fought, by a greater number of athletes and nations. Whilst this makes these events more exciting to watch it can have one big downside – you can’t always tell who won!
There are many events at the Olympic Games where competition is so close, particularly athletics, swimming and track cycling. The winning margins in these sports are getting smaller and smaller all the time – a lead the size of Bolt’s in Beijing and London is not the norm. Several sprint events are already timed to the nearest 1000th of a second and that isn’t always enough to determine a winner. So what else can be done? Step forward technology.
There are two main areas of technology which are presently used to increase the accuracy of timing races: Cinematographic techniques and Pressure sensors.
The photo-finish is now a fairly common term when we talk about sport, especially sprint events and this was one of the first methods introduced as a way of getting around the imprecise timing methods. An image is produced, as shown above, that shows all competitors on a horizontal time scale and allows officials to give each athlete a precise time and award medals appropriately. The first photo-finish in an Olympic games was in the final of the 100m sprint at the last London games in 1948. Timing was only recorded to the nearest 0.1s and both Harrison Dillard and Barney Ewell ran a time of 10.3s. Fortunately they had setup the camera on the finish line and could determine that Dillard had won.
Photo finish from the Olympic 1948 100m final
High speed video analysis is also used on the finish line in track cycling to determine the winner in close races. Occasionally in the sprint events, the finishes are so close they cannot even give riders a separate time and rely upon this technology. The video below is a great example of how close track cycling can be – Max Levy of Germany (in white) was awarded the win by a margin of 0.8mm! This decision making is done using a camera that looks across the finish line, perpendicular to the direction of motion of the cyclists and allows a similar image to that used above to be produced in order to decide positions. However, in exceptional circumstances, such as at the recent men’s Keirin final at the London 2012 Olympics, even this video analysis cannot split all the riders and in this case the bronze medal position was shared. So, is there a better method for determining race positions? Do we need a new technology to solve this problem?
Quite often, races in swimming are decided by hundredths of a second. In order to decide who has won the officials can’t rely upon sight or visual aids. In order to aid decisions, pressure plates are fitted into the wall of the swimming pool at either end, these record a finish time when the swimmer applies a specified force. This seems like a fair solution. Video analysis, as used in cycling wouldn’t necessarily be ideal as a view of an athlete under the water surface for example may not be accurate. With the use of the pressure plates, every little edge can count. If you have slightly longer arms or fingers that could be enough to see you win. Even the phase of your stroke counts, as it did in the Men’s 100m butterfly final in the Beijing Olympics, which was #7 of Michael Phelps’ 8 gold medals. Phelps won the race due to his final swing for the wall being in the air, as opposed to Milorad Cavic lunging for the wall through the water (which is slower due to the difference in density). This difference was enough for Phelps to overtake for a last moment win:
There is a fantastic picture sequence in this presentation which illustrates just how small this winning margin was. [Phelps has since fallen victim to the same mistake in the 200m Butterfly final in London, losing out to Chad Le Clos]
So, there is a lot of technology deciding which athletes win medals at major championships and there are examples which show some of these solutions may no longer be good enough as the performance levels of the world’s elite become closer and closer. This is surely going to lead to the continued inclusion of technology in race officiating. Is this good for us though? Is it worth going to watch live sport if you aren’t going to know who’s won until 30s later when the replays show you on a big screen? Or are you better off sat at home with your 3D, HD, instant analysis?