Goal-line technology (or Goal Decision System) refers to an electronic means to determine when the ball has completely crossed the goal line with the sole intention to assist referees in awarding a goal or not. In the wake of controversial calls made in the Premier League, 2010 World Cup and the Euro 2012 FIFA have rather reluctantly accepted the need for GLT but insist the function is not to replace the role of the officials, but rather to support them in their decision-making. The introduction of the so-called "fifth official", i.e. the extra assistant referee standing beside the goal-line, was partly in order to facilitate in such situations.
FIFA’s decision to incorporate goal line technology is largely attributed to a 2010 World Cup game between England and Germany. Frank Lampard’s goal against Germany was disallowed despite television network footage showing it crossing the goal line before bouncing into the German goalkeeper’s hands. The game ended with a German victory, 4-1.
The International Football Association Board (IFAB) officially approved the use of goal line technology in 2012 and for the first time goal-line technology in a competitive match has been used at the 2014 FIFA World Cup in Brazil .
The GoalControl system was installed in each of the 12 stadiums. Each stadium is equipped with 14 high-speed cameras positioned around the field, with seven cameras focusing on each goalmouth (the area directly in front of the goal). The system was developed by the Fraunhofer Society in association with Select Sport . It works by detecting the passage of the ball using magnetic induction. A low frequency magnetic field is generated around the goal, which is monitored by coils installed in the goal posts and crossbar. The ball is fitted with a passive electronic circuit embedded between the leather outer and inflatable inner layers. Software monitors the condition of the magnetic field in the goal and can detect the change that occurs in it due to the passage of the coils in the ball over the line. Once detected, the system sends an encrypted radio signal in real time to a wrist watch worn by the referee, which both vibrates and displays a message that a goal was scored.
The first World Cup goal to be be award using GLT was in a group stage match between France and Honduras, the Honduran goalkeeper Noel Valladares dropped a shot from Karim Benzema into the goal.
Advocates for goal-line technology maintain it will significantly reduce refereeing errors during play (up to 30% of the referee’s decisions made during a game) but the systems still has critics mainly within FIFA itself. Critics believe the new technology will impact on the human element of the game and remove the enjoyment of debating mistakes. Without doubt the new technology is prohibitively expensive particularly for smaller/poorer football associations. Advocates contend that any extra help for the referee should outweigh arguments that it would lead to non-uniform rules (since not all football associations would be able to implement it). Goal line technology will likely remain a part of the World Cup in future years and many believe goal line technology will enable referees to focus more on off sides which is important as those are still entirely monitored by humans.
The electronic goal-line technology to be used in the 2018 FIFA World Cup Russia™ has been in use in all FIFA men’s senior events since 2012 FIFA Club World Cup Japan competition and was used for Women’s World Cup in Canada for the first time. The electronic goal-line technology will automatically register the goal and instantly alert the referee to the fact that the football has crossed the goal line. The following goal-line systems have been approved for use: GoalRef, Hawk-Eye, and GoalControl-4D. Recent reports of errors with GoalControl system during the Coupe de la Ligue quarter-finals, have cause d some concerns however and the use of the technology was suspendended. The Premier League, Bundesliga, Eredivisie and Italian Serie A all use a separate company, Hawk-Eye, for their goal-line technology, while GoalControl's system was used during the 2014 FIFA World Cup. Video Assistant Referees (VAR) has created confusion in the first full season of live trials which now include more than 1,000 games worldwide. Unease over the technology has largely centered on the lack of clarity for fans, coaches and television audiences over when and how decisions are reached using video review. The International Football Association Board (IFAB), FIFA have agreed Video Assistant Referees (VAR) will be at the World Cup in Russia 2018.