In time past, referees were left with the sole decision of deciding if a ball crossed the goal line or not. And most times, that is not effective, because the referee can not see everything on the pitch. However, with the goal line technology, that problem was solved. In this guide, we would see some more benefits of the goal line technology.
What is the Goal line Technology?
Goal-line technology is a technical means of instantly determining whether the whole of the ball has crossed the goal line.
The International Football Association Board requires that goal-line technology (GLT) does not interfere with the game. As a consequence, the requirements were set up to determine that only the match officials are to receive a signal to indicate whether or not the entire ball has crossed the line.
The information is transmitted within one second which ensures an immediate response from the referee. Due to this design, there are no stoppages or other forms of interference in the game. The match officials are the only ones to receive the signal on their watches. Unless there is a conscious choice by the competition organizer to show a replay, the information is only available to the referee and helps in challenging situations.
How Does Goal-line Technology Work?
In essence, goal-line technology uses data gathered from multiple sources to track the path of the ball and detect when it completely crosses the goal line. In most cases, it is fairly easy to see if a goal has been scored, but fast-paced plays, rebounds, and saves can make it hard for referees to make a decision by eye—that’s where goal-line technology comes in.
Since 2012, FIFA and the International Football Association Board (IFAB) have approved the use of certain systems in official games. Certified installers must verify their systems using a special test, which takes into consideration the many variables in each stadium, such as lighting, climate, and architecture. Because goal-line technology is expensive to install and maintain, it is currently only used at the highest level of the game, including in top European leagues and the Men’s and Women’s World Cups.
Camera Tracking and Other Tools
One common method for tracking the ball is to use camera technology. Hawk-Eye, the first ball-tracking technology in action, uses cameras to triangulate and track the ball’s location.
- Hawk Eye
The Hawk Eye technology is the most high-profile system amongst these varying technologies. It uses fourteen sophisticated cameras placed around the stadium at different positions pointing towards the two firm goalposts, seven focused on each.
This technology isn’t something novel and has been widely used in other sports for more than a decade, most noticeably in cricket, tennis, and snooker. The high-speed cameras track the ball with high accuracy and use triangulation to calculate its precise position relative to the goal line.
Triangulation is a geometric technique of calculating the distance and position to and of, respectively, an unknown point with the help of two known points. As the name suggests, the system forms triangles between these three points and uses the angles between them to determine the whereabouts of the third unknown. The system software then creates a 3D image of the ball relative to the line.
This technology can produce reliable results even when the view of some cameras is obstructed by players’ bodies. This is because only three of them are required to implement triangulation and generate an image. Therefore, even if the view of a few cameras is hindered, the others can take over seamlessly.
The software calculates the ball’s location in each frame by identifying the pixels that correspond to the ball. A better perspective of how meticulously competent these cameras are can be acquired when you consider that a kicked football flies through the air at an average of 120 km/hr!
If the ball fully crosses the goalmouth, an encrypted signal is transmitted to the referee via a watch or an earpiece within half of a second, alerting them to a goal. Remember, the ball must fully cross the line for it to count as a goal.
Hawkeye cameras also allow for evaluating and simulating the trajectories of an object if it had been allowed to continue its motion or if its motion hadn’t been interrupted by an obstacle. For instance, the simulated trajectory of a cricket ball can determine whether it would have hit the stumps had it not hit the batsman first.
This Hawkeye system was first featured in the 2013-2014 Premier League in the U.K. Since then, it has also been adopted by the other Ivy leagues of football: Bundesliga, La Liga, and Serie-A.
- Goal Control 4-D
Similar to the Hawk-Eye technology, Goal Control 4-D uses 14 high-speed cameras installed around the stadium pointing at the goalposts. Seven cameras are dedicated to each frame. They calculate the ball’s position and trajectory to eliminate the ambiguity regarding the ball crossing the goal line.
One major limitation of this system is the high cost of implementation. Even though it was used in the 2014 World Cup, it was dismissed by the top-flight leagues due to its higher cost.
Another technology that is not widely known is the Goalminder, which uses cameras mounted on the insides of the posts, rather than around the stadium, to track the ball.
Goal-line technology criticism
Imagine scoring what could be one of the most important goals of your career and then having it stripped away from you. This is what happened to Frank Lampard during the FIFA World Cup 2010 when he scored a fantastic 2-2 equalizer for England against Germany. Only he didn’t, as the officials failed to see the ball bouncing close to a meter behind the German goal line.
Germany won the match 4-1, but controversy followed. What would have been the match outcome if Lampard’s equalizer had been acknowledged? This incident, among many others, led to the implementation of Goal-line technology.
With Goal-line technology as an extra on-field tech assistant to ease the human eye, the referee becomes flawless on crucial goal-line decisions. Or at least close. Back in June 2020, a game between Aston Villa and Sheffield ended goalless after the goal-line system failed. Villa keeper Orjan Nyland accidentally carried the ball over the line, but the highly advanced system failed to notify the referee. A bizarre error that we are unlikely to witness again any time soon.
What’s more, a current point of critique is the impact technological advances have on the natural game flow. Even though GLT and VAR have been implemented to make the sport fairer, the technologies have been criticized for slowing down the game as well as taking some of its human elements away.
Types of Goal Line Technology
The currently available systems are based on two different approaches (FIFA, no date-b). Camera-based systems use seven cameras per goal to determine the location of the ball (Gibbs, 2014). If the ball crosses the goal line, the systems transmit this information within one second and the referee gets an indication on his watch (FIFA, no date-a). Camera-based systems are ‘Hawk-Eye’ and ‘GoalControl’ (Gibbs, 2014).
Magnetic-field-based systems equip the goal with cables creating a magnetic field (FIFA, no date-b). Moreover, the ball contains an electronic circuit arguing that this significantly changes key components of the game. However, a change in the electromagnetic field is detected whenever the ball crosses the goal line. Again the referee gets an indication on his watch (FIFA, no date-a). ‘Cairos-GLT-system’ and ‘GoalRef are magnetic-field-based systems (Gibbs, 2014).
These two types of GLT represent two different formats/designs. As Geroski (2003, p.106) states the competition between these designs will end up with one dominant design and the other will probably disappear. According to Geroski (2003, pp.112-113), a dominant design fulfills three roles:
- Combining the needs and claims of the customers
- Defining the need and the relationship with complementary products
- Defining essential characteristics
A dominant magnetic-field design would consider the referee’s watch and balls equipped with electronic circuits as complementary products. Further, cables and circuits would become key characteristics. A dominant camera-based design would consider cameras as key characteristics and the watch as complementary products.
It is difficult to predict which design will become the dominant one. The camera-based systems tend to be in an advantageous position. The ‘Hawk-Eye’ technology is currently in use in several leagues and the ‘GoalControl’ technology was used at the 2012 Club World Cup and the 2014 World Cup.
- The referee can make the best possible use of the information given by GLT while declaring the results.
- A German company Cairos Technologies AG and Addidas together designed this system for the convenience of officials to mark fair decisions in football matches.
- The technology is based on the principles of the magnetic field, having a sensor inside it that sends data to the main server, after measuring the magnetic field deflections if a ball crosses the goal line. Within an infinitesimal time, the signal is conveyed to the referee’s watch after which he declares the goal.
- This technology is used only in major football competitions being much more expensive. Recently, it has been used in the top domestic leagues in Europe.
- The main aim of Goal-line technology is to provide more accurate information i.e. to determine whether the ball has completely crossed the goal line or not.
In conclusion, Goal-line technology lets the referees know if a ball has fully crossed the line or not. It’s very quick and doesn’t waste any time on the pitch, all the referee has to do is look at his watch and it will let him know if it’s a goal or not.