How does goal line technology work in football?

[BW 0]

In tennis they wait till after the point finishes then get the hawk eye to have a look how can we do this in football do we wait until the ball goes out before we check which could be a number of minutes to be honest? Anyone know?

[Bethnal Yellow and Green 1,557]

The ref and his assistants will be notified (via his watch) instantly if the ball crosses the line.

[BW 0]

Well then i am all for it thanks bethnal. Sounds great

[PurpleCanary 5,554]

The assumption seems to be that the technology will show that the ball has crossed the line when the officials have thought or ruled otherwise, as in certain high-profile cases. My suspicion is that generally the technology will rule as still in play balls that look to the naked eye to have crossed the line. The point is that the whole of the ball has to be beyond the whole of the line. A ball can bounce down off the crossbar without touching the line and still not have crossed the line. Providing some part of the ball overlaps the line it is still in play.

[Bethnal Yellow and Green 1,557]

There are two systems proposed; Hawkeye and GoalRef.

 

We all know Hawkeye from tennis and cricket where it works well, but in football it is more questionable - it requires 6 cameras to be placed around the goal (2 behind the goal on the stand, 2 to the left side and 2 to the right), this of course isn''t cheap and not all stadiums will be able to house the cameras easily. Also, 25% of the ball needs to be visable to the cameras, if there is a crowded penalty box, or the keeper has his hand on the ball this might not be possible. The benefit is it will be able to produce those nice graphics like at Wimbledon.

 

GoalRef is much more simple - it is a chip inside the ball which reacts when it breaks a magnetic field placed inside the goal. However there are some issues in regard if the ball hits the side-netting and bulges into the goal.

 

Neither system is perfect as I understand it, and both are expensive - I''ve seen £250,000 quoted for Hawkeye and clubs will have to pay for the installation themselves.

 

I imagine Premier League will go for both GoalRef and Hawkeye, lower Leagues will probably just use GoalRef.

[Son Ova Gunn 165]

lets face it, even some cling film streached across the goal would of been more use during the euro''s than those extra two ''assistants'' on the goal line.

Ive heard £150,000 banded around but dont think anyone really knows the costs yet, both systems only licenced today i think but if you are a team in Div 1 or 2 that amount could be your entire seasons transfer kitty.

 

 

[J 0]

[quote user="Bethnal Yellow and Green"]

There are two systems proposed; Hawkeye and GoalRef.

 

We all know Hawkeye from tennis and cricket where it works well, but in football it is more questionable - it requires 6 cameras to be placed around the goal (2 behind the goal on the stand, 2 to the left side and 2 to the right), this of course isn''t cheap and not all stadiums will be able to house the cameras easily. Also, 25% of the ball needs to be visable to the cameras, if there is a crowded penalty box, or the keeper has his hand on the ball this might not be possible. The benefit is it will be able to produce those nice graphics like at Wimbledon.

 

GoalRef is much more simple - it is a chip inside the ball which reacts when it breaks a magnetic field placed inside the goal. However there are some issues in regard if the ball hits the side-netting and bulges into the goal.

 

Neither system is perfect as I understand it, and both are expensive - I''ve seen £250,000 quoted for Hawkeye and clubs will have to pay for the installation themselves.

 

I imagine Premier League will go for both GoalRef and Hawkeye, lower Leagues will probably just use GoalRef.

[/quote]Well as far as I know they have said that the crowd and everyone else wont get to see any replays of it or anything like that - it will only be available to the refs and they still have the final say whether to give the goal or not. GoalRef and the bulging of the net for example, is then not an issue as there wont be any announcement or replay or anything like that that signifies a goal apart from to the ref, who can deny the so called goal given by the system knowing that it hit the side of the net.Surely hawkeye could implement the cameras into the goal posts/bar.

[JF 694]

Football doesn''t need expensive goal line technology. There are cameras and monitors at every match, It just needs the 4th official to be watching the monitor and then the ref can consult him on contentious decisions, Saving every club a small fortune.

[Ben 0]

We''ve seen before how the cameras that are already at football grounds, plus extra ones which are brought by Sky doesn''t always make it clear if the ball has crossed the line. For example the Champions League Semi-final between Liverpool and Chelsea. Nobody knows to this day if the ball crossed the line or not but goal line technology would have picked that up. So it is needed for the very close calls.

[Aggy 752]

Just for the record, in tennis they don''t necessarily have to wait until the point ends, it''s just that obviously if someone calls out then the point has ended.

If you''re watching the Tsonga Murray game though, you will have just seen Tsonga appeal for a point half way through a rally. His call was wrong and he defaulted the point as a result.

[BW 0]

Why would you be watching Murray the anti English Basta*d

[mikemiddle 0]

I was hoping for a big screen to be put up infront of the hotel so we can watch replay of goals and the hawkeye replay and the f.a could pay for it .But if we have to pay no chance.