Goal-line technology may be used in major soccer competitions as soon as December after the sport's rule-making body sanctioned its introduction following high-profile errors at the World Cup and the European Championship.
The International Football Association Board on Thursday unanimously approved allowing the Hawk-Eye and GoalRef systems, which use technology to tell whether the ball has crossed the goal line. The systems will aid officials, who will still base their rulings on what they see on the field.
"Over the past few years, there have been a number of occasions where mistakes have clearly occurred in football," Scottish Football Association Chief Executive Officer Stewart Regan, an IFAB member, said Thursday at a news conference in Zurich. "Anything that assists the referee to make correct decisions is good. This is a historic day for football because we now have the technology to assist the referee."
It's planned that the systems will begin at the Club World Cup in Japan in December. They'll also be used at the 2013 Confederations Cup and 2014 World Cup tournaments in Brazil. National associations can decide on whether, and how, they implement the systems.
"The only ability to score points in this sport is when the ball crosses the line," said the IFAB's Alex Horne, general secretary of England's Football Association. "There are very few occasions where the ball crosses the line and we believe the ability to help the referee is entirely appropriate."
The technology will only be used to determine where the ball has crossed the goal line and not extend to other parts of the field, for example in deciding offsides.
"We do not believe that it is appropriate for technology to creep out on the field and interfere with decisions," Horne added. "We are deliberately drawing a line. The goal-line is where it stops."
The ultimate decision will remain with the referee.
"Neither system is infallible," Football Association of Wales Chief Executive Jonathan Ford said. "They are systems to aid the referee. The decision of the referee has to be final."
The IFAB sets the rules for the game, with the UK's four so-called home nations -- England, Wales, Scotland and Northern Ireland -- each having a vote, while the sport's governing body, FIFA, has four.
A disallowed goal by England's Frank Lampard against Germany at the 2010 World Cup pushed FIFA President Sepp Blatter to re-examine the issue, two years after the sport's rule makers decided not to pursue the technology. FIFA had been criticized by fans, players and match officials over its failure to adopt video or computerized ways of monitoring the ball's flight.
Blatter increased his support for the new technology after Ukraine was denied a goal against England last month in their Euro 2012 group match.
An assistant referee patrolling the goal line about eight yards (7 meters) away didn't award a goal. Tournament organizer UEFA, whose president Michel Platini has lobbied against the introduction of goal-line technology to assist in such matters, used an extra official at each end of the field for the first time at the four-yearly championship. The IFAB also approved the continuance of this practice.
"We opened discussion after what happened in World Cup 2010," FIFA Secretary General Jerome Valcke said. "We have the feeling that we can be confident to look at the future with these systems."
England's Premier League welcomed the IFAB decision and said it hoped to introduce goal-line technology "as soon as is practically possible." It could be brought in during the second half of the 2012-13 season, Horne said.
The Hawk-Eye system uses high-speed cameras placed around the stadium to track the flight of the ball and sends an electronic message to the officials when it crosses the goal line. The GoalRef system uses three magnetic strips inside the ball which trigger sensors on the goalposts and crossbar if it crosses the line.
Valcke said it would cost between $150,000 and $250,000 to implement the systems in stadia and that costs would come down as more companies develop the technology.
In the US, replays are used more widely in the National Football League, where coaches can challenge decisions including the validity of a score or whether a receiver catches the ball in bounds.
Since October 2008, National Basketball Association referees have been able to use replays to decide whether a field goal was for two or three points, or whether a shooter was fouled beyond the 3-point arc. They can also use video to determine if a 24-second shot clock violation occurs prior to a field goal or foul. Before that, officials used video to review buzzer-beating scores.
National Hockey League officials can watch replays to determine the legality of goals.
Sports such as rugby, cricket and tennis have also turned to video evidence to ensure decisions are correct, with players able to challenge line calls in tennis via the Hawk-Eye system.
"The notion of the referee controlling the game is universal," Horne said. "All we're doing here is adding an assistance to let him do his job."