Goal-line technology has finally won approval following a vote
by International Football Association Board
(IFAB) members in Zurich on Thursday.
There are a few hurdles still to negotiate, but it
could be introduced into the English Premier League midway through the
2012-13 season.
Here, BBC Sport asks - and answers - the big questions.
So, after years of debate, is goal-line technology going to be introduced at all matches?
The International Football Association Board voted
unanimously in favour of introducing the technology, leaving it up to
individual associations to decide whether to implement it into their
respective competitions.
Fifa used to be against it, so what changed?
Fifa dropped its long-standing opposition to its introduction in 2010 following
Frank Lampard's disallowed goal against Germany at the World Cup in South Africa.
His shot hit the bar and bounced down over the line, but a goal was
not given by officials. Fifa president Sepp Blatter apologised to the
English Football Association (FA) after the incident.
Speaking to BBC Sport this week,
Blatter said: "That was the moment for me to say: 'You can't afford
for something similar to happen in the next World Cup.' We could say it
is a historic day for international football."
So once Fifa changed its stance, how did it go about finding a suitable system?
Eight systems were initially tested by an independent
body. Each company had to demonstrate their technology adhered to Fifa
benchmarks. These included notification of a goal being sent to the
referee's watch within one second of the ball crossing the line and
strict standards on accuracy. Two companies proceeded to the second
phase of testing.
GoalRef and British-based Hawk-Eye were tested again to
check their accuracy in "real-world" scenarios - including in poor
weather conditions, while floodlights are being used and when players
are moving or standing close to the goal posts. They were both
successful.
Tell me more about the two systems that have been approved.
Hawk-Eye's system uses six cameras, focusing on each
goal, to track the ball on the pitch. The system's software uses
"triangulation" to pinpoint the exact location of the ball. If it
crosses the goal-line, an encrypted radio signal is sent to the
referee's wristwatch to indicate a goal has been scored. The whole
process takes less than a second to complete.
GoalRef uses a microchip implanted in the ball and the
use of low magnetic waves around the goal. The system then detects any
change in the magnetic field on or behind the goal-line to determine if a
goal has been scored. The process takes less than one second, with the
result electronically relayed to the referee.
So two companies have been approved - what happens now?
The technology will first be used at December's Fifa
Club World Cup and, if successful, at the 2013 Confederations Cup and
2014 World Cup.
The Premier League wants to use it "as soon as
practically possible". It will decide, through consultation with member
clubs, its preferred system and then make a decision about cost and when
to implement it. The Football League will also discuss the matter with
its 72 clubs.
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There are big questions for the FA, including whether
the systems would be allowed in the FA Cup. Top-flight clubs could, for
example, use goal-line technology for home ties, but it might not be
available to teams from lower divisions.
And what about the Champions League? Isn't Uefa against it?
Uefa president Michel Platini believes it is wrong to
implement goal-line technology due to the infrequency of goal-line
incidents within games. It means there could be a situation where
technology is used in Premier League and World Cup games but not the
Champions League and Europa League. However, Blatter is confident
Platini, who is in favour of using more assistant referees instead, will
change his mind.
"He is more afraid that once technology comes in, it
will go from the goal-line towards the penalty box or whatever," said
Blatter. "But I am sure with this unanimous decision of the
international board that he will follow. He cannot go against history
and this is new history."
Who is paying for it?
That is another unanswered question. The Premier League
is likely to centrally fund it for its member clubs, but what about
everybody else? Commercial sponsorship is another possibility and it is
believed the Football League could look at that option.
Then there is international competition. England would
happily pay for goal-line technology, but a smaller nation may not have
the funds or not want it. That is when the issue might become
complicated. So England could have it and others would not.
And how much will it cost?
Fifa general secretary Jerome Valcke has estimated the
cost to be between £120,000 and £160,000 for each system. However, he
said he expects that figure to fall over time.