The use of technology in soccer for things like goal line calls, offside, and more has always been experimental, and even then has been controversial. While arguing over a referee’s call is often a soccer fan’s favorite pastime, few fans or officials support its use in the beautiful game. However, more often than not the debate is about technology’s impact on the flow of the game, not accuracy. Yet as technology is evaluated for use in soccer, we cannot overlook the fact the technology is imperfect and subject to errors.

In other sports, the use of technology has gone much farther, with video replays and more advanced technologies in official use. A case in point is international tennis, which has adopted a ball flight tracking system to rule on challenged calls called Hawk-Eye. Using high speed cameras, the system tracks the flight of tennis balls and can provide a 3D recreation of the ball bounce in judging if it was in or out. This spring, unified rules for it’s official use in international tennis were adopted.

Anyone who watched Wimbledon 2007 knows the technology was called into question by Roger Federer. TV replays, Roger, and the umpire ruled the ball out, but the Hawk-Eye system ruled it in, by 1mm. There’s only one problem – the average error of the Hawk-Eye system is 3.6mm. Yet the rules did not stipulate a minimum variance where the system would be ignored. An upcoming paper from Cardiff University researchers will show that systems like the Hawk-Eye can be wrong, and they should not be relied on to make final calls. They propose something called the Automated Decision Principle:

The paper puts forward the Automated Decision Principle. This states that automated sports decision aids should not correct but should reproduce human systematic errors — the typical errors made by human judges and viewers such as calling a tennis ball `out when it looks out to everyone even if the electronics suggest it might just have been in. At the same time, the devices should be used as they are now to correct or reduce human random errors, which come from lapses of concentration, an obscured view or very fast action – but the fact that the machine can also make mistakes should always be clear. If adopted, this Principle, would involve significant changes in the way devices such as Hawk-Eye are currently used in sport.

It’s an interesting concept. In the end, it makes clear that tracking technologies like this and many others should never be used within their margin of error. Another article in the IEEE Spectrum provides much more detail. There is such a thing as ‘too close to call’ and is one reason why the NFL replay rules call for ‘conclusive evidence’. The makers of the Hawk-Eye instead chose to show why TV replays can be deceiving. Yes, replays can be deceiving and camera placement is key. But the facts remain that the system was used to overrule a call that based on the system’s own published margin of error was ‘too close to call’.

The reason for bringing this up here is that ball technology is going to be used in soccer someday. It is inevitable. The key is making sure when it is adopted that the rules ensure it doesn’t drastically change the flow of a soccer match AND account for any technical system’s margin of error and when something is too close to call – you go with what the referees said first.

H/T Slashdot