Unlike other sports, soccer has taken some convincing to adjust to the technological times we live in. Where other sports benefit from using instant replay, it is still frowned upon in soccer. Goal-line technology began in the same way. Critics were outspoken against it whereas players were begging for it. Countless examples of ghost goals were seen in various stages of the game, but none arguably more outrageous than Frank Lampard’s “no goal” against Germany during the elimination stages of the 2010 FIFA World Cup in South Aftica. Then, FIFA, who had tested but discarded goal-line technology, was forced to reverse their position and begin the search for a system. Luckily for them, there were–and still are–plenty of systems available.
Below are the top four goal-line technology systems in fútbol.
GoalRef
Used for the first time during the 2012 FIFA Club World Cup, this German system uses the basic principle of magnetic induction. A magnetic field generated around the goal is altered when the ball, fitted with a passive electronic circuit, crosses the goal line. The software monitoring the magnetic field then sends an encrypted radio signal to a special wristwatch worn by the referee.
GoalRef technology has been used in the Danish Superliga; and is approved by the International Football Association Board for use in the professional game.
Hawk-Eye
A popular English system in sports since it is used most notably in tennis, the Hawk-Eye is also approved by IFAB for use in official matches. It utilizes seven high-speed cameras situated around the stadium to track ball movement via triangulation. Aware of the ball’s location thanks to the triangulation, the system knows when it has crossed the goal-line and can send a signal to the referee’s wristwatch.
Hawk-Eye is not perfect, but its margin of error of 3.6mm is better than the 3cm margin of error allowed by FIFA. It is, however, expensive, and although the system was rolled out for use in the English Barclays Premier League in the 2013-2014 season, a majority of clubs in the two top tier leagues in Germany decided against it, citing the system’s high price.
CAIROS
The Adidas-backed CAIROS GLT system is one-of-a-kind, in that it uses an electronic system that has sensors placed inside the ball itself. It also utilizes electromagnetic strips buried under the goalposts. Once the ball crosses the goal line, the sensor inside measures the magnetic field and sends this data to receivers behind the goal. These receivers send encrypted data to a computer, which determines whether the ball crossed the line. If it did, a signal is sent to the wristwatch worn by the referee.
CAIROS might be backed by Adidas, and is also approved by IFAB, but the system’s cost is one of the main concerns. The other being having to actually dig into the pitch to install it.
GoalControl
Those of us who watched the 2014 FIFA World Cup in Brazil caught GoalControl in action. The German system was chosen by IFAB and FIFA after numerous testing and comparisons between all of the above mentioned systems. GoalControl includes 14 cameras installed around the rim of the stadium. Seven of these cameras are focused toward each goal and are connected to a central computer, where all ball movement data is sent. The computer then analyzes the triangulation data and decides if the ball crossed the line, before sending a vibration and signal to the referee’s watch, all within fractions of seconds. The system also creates a virtual image of the field, filtering officials and players, to show the location of the ball, which is then broadcasted inside the stadium and on television. GoalControl technology received positive feedback from its performance in Brazil; and we’ll be sure to see it again in this year’s FIFA Club World Cup in Marruecos.
After undergoing vigorous testing and seeing action during various tournaments, we have seen than each of these systems has their pros and cons. All of them work at differing speeds, and none are cheap, but they certainly make the game fairer; and, most importantly, do not interrupt the flow of the match. It is only a matter of time before the majority of fans, and more leagues around the world, fully embrace goal-line technology; and we will all be left asking ourselves how we went so long without it.