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Final score saying Holtby effort went over the line

Started by Toby Ward-Smith, April 05, 2014, 05:14:18 PM

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The Enclosurite

I think it would've actually been the opposite as the two goals would've been give to us.

Quote from: F(f)CUK on April 06, 2014, 10:30:42 AM
I think the goal line system is brilliant. If it were not in place, this thread would have been 3 times as long and talking about injustice for us against Newcastle and Villa.
¡COYW!

ChrisBairdOhh

Just a few things, which you can find from simple googling.

- The Hawkeye system has 3.6mm precision, though it can only work if at least 1/4 ball is visible. FIFA only required the precision to be 3cm. So it beats that by nearly an order of magnitude.  I'm not sure how they deal with small error, I assume they always give the defence the benefit of the doubt  

- The system doesn't work by simply 'picking up the centre of the ball'. It uses camera triangulation to find the exact shape of the ball. I'm not sure why the image they release shows the ball as circular, as it's only the point closest to the line that matters, maybe they don't process the image to show it.

'Even Hawkeye in tennis takes into account the shape of the ball hitting the surface.'
- yes, but you never see a still of the ball hitting/missing the line. You see the imprint it leaves, this is always elongated because of the ball changing shape, but also as the ball will roll slightly on contact with the surface.

- Akf - I'm not entirely sure what you're saying, that Hawkeye deliberately chose to not give the goal by ignoring later images of it over the line? The cameras constantly film the goal line and they would use the image of it at it's furthest point. It's not some villa fan sat in an office choosing which point to use...it's an independent, computerised system.

Here's some more information about it-  http://www.hawkeyeinnovations.co.uk/page/sports-officiating/football

PokerMatt

I've read the Hawkeye page before, but I struggle with your answer that the cameras pick up the exact shape of the ball even if it has only seen 1/4 of it? Surely if they cannot see the full ball then there's some guesswork involved still?

"- yes, but you never see a still of the ball hitting/missing the line. You see the imprint it leaves, this is always elongated because of the ball changing shape, but also as the ball will roll slightly on contact with the surface."

Not sure how that clears it up? The still image seen above of the ball and the line is still not a photo is it? The tennis ball is always of where the bounce is so the ball is always out of shape, but my point is that even a football changes shape once kicked in the opposite direction so the ball being round in the shot to prove it wasn't in is misleading.
Follow me: @mattdjourno


fulhamben

Quote from: ChrisBairdOhh on April 06, 2014, 10:58:49 AM
Just a few things, which you can find from simple googling.

- The Hawkeye system has 3.6mm precision, though it can only work if at least 1/4 ball is visible. FIFA only required the precision to be 3cm. So it beats that by nearly an order of magnitude.  I'm not sure how they deal with small error, I assume they always give the defence the benefit of the doubt  

- The system doesn't work by simply 'picking up the centre of the ball'. It uses camera triangulation to find the exact shape of the ball. I'm not sure why the image they release shows the ball as circular, as it's only the point closest to the line that matters, maybe they don't process the image to show it.

'Even Hawkeye in tennis takes into account the shape of the ball hitting the surface.'
- yes, but you never see a still of the ball hitting/missing the line. You see the imprint it leaves, this is always elongated because of the ball changing shape, but also as the ball will roll slightly on contact with the surface.

- Akf - I'm not entirely sure what you're saying, that Hawkeye deliberately chose to not give the goal by ignoring later images of it over the line? The cameras constantly film the goal line and they would use the image of it at it's furthest point. It's not some villa fan sat in an office choosing which point to use...it's an independent, computerised system.

Here's some more information about it-  http://www.hawkeyeinnovations.co.uk/page/sports-officiating/football
yep, I think the system is here to stop the lampard vs Germany blunders happening again as opposed to the Geoff hurst type that can still be argued today. if it gives a goal that's a foot over that the lino and ref have missed then its doing its job. my only query is can a ref and lino over rule it if the ball is well over and hawkeye doesn't give it?
CHRIS MARTIN IS SO BAD,  WE NOW PRAISE HIM FOR MAKING A RUN.

ChrisBairdOhh

Well yes, there will always be some 'guesswork' 'or extrapolation of the ball, but it is not simply taking a centre point and assuming a sphere.  The number of cameras means that,  especially in this case when a number of cameras would have been able to see the whole ball, they can reconstruct/measure the exact ball shape.

I agree with your point about the ball shape, I'm saying that in tennis replays you see the mark of the ball. Not a squashed ball.

As I said in my post, I don't know why they show the computer generated image of the ball as perfectly spherical. When you watch the live footage they show the video, then an overhead photo, then convert to cartoon without players etc. I don't know why they do it like that, and it is misleading if you are trying to interrogate it that much.  All I mean is it is based upon the live videos. Not as some have said of an imaginary ball based upon it's centre point. So the live video images would show the ball shape.

ChrisBairdOhh

Not sure about that Ben, I'm sure that if they were convinced it was a goal they would have the power to overrule the decision. I.e. If it hits the back of the net they won't be checking their watch to see.


PokerMatt

Quote from: ChrisBairdOhh on April 06, 2014, 11:19:25 AM
Well yes, there will always be some 'guesswork' 'or extrapolation of the ball, but it is not simply taking a centre point and assuming a sphere.  The number of cameras means that,  especially in this case when a number of cameras would have been able to see the whole ball, they can reconstruct/measure the exact ball shape.

I agree with your point about the ball shape, I'm saying that in tennis replays you see the mark of the ball. Not a squashed ball.

As I said in my post, I don't know why they show the computer generated image of the ball as perfectly spherical. When you watch the live footage they show the video, then an overhead photo, then convert to cartoon without players etc. I don't know why they do it like that, and it is misleading if you are trying to interrogate it that much.  All I mean is it is based upon the live videos. Not as some have said of an imaginary ball based upon it's centre point. So the live video images would show the ball shape.

So presumably they make the sphere from where the camera has picked up the ball to be closest to the line? I.e. the camera saw it was 2mm or whatever from going over the line and drew the sphere from that point?

It still doesn't make it clear how they decide the position if only the quarter of the ball that looked most over the line was showing, with the ball potentially misshapen.
Follow me: @mattdjourno

Artful Dodger

I'm just glad it didn't matter in the end! And how incredible is it that the 3 games where we have been 'denied' by the technology, we have ended up winning anyway! I suppose we can be pragmatic about it on that basis and hope at some point, we benefit from what would otherwise have been a goal against us!
Faber est suae quisque fortunae

ChrisBairdOhh

I assume they just create the modelled ball shape based on what is available. So if they have all of the ball in view from some cameras, as I imagine it would have been in yesterday's game. So they draw the ball from that - as you said probably not a sphere due to compression.
The cartoon sphere you see is probably just created, as you said, to show the position of the ball relative to the line. I am guessing here, but it's probably just done to speed the process up and to save computing power.

Agreed about if only 1/4 is visible, but they have said that such cases are very rare because only 2 cameras need a view to pick up the position. There would need to be a lot of bodies to prevent much being seen. I'm trying to find some data on ball compression but can't really find anything on how much it deforms.


PokerMatt

Quote from: Artful Dodger on April 06, 2014, 11:39:17 AM
I'm just glad it didn't matter in the end! And how incredible is it that the 3 games where we have been 'denied' by the technology, we have ended up winning anyway! I suppose we can be pragmatic about it on that basis and hope at some point, we benefit from what would otherwise have been a goal against us!

One of them was the WBA game I thought? Vydra's late equaliser squirmed over the line and was given on GDS.
Follow me: @mattdjourno

ChrisBairdOhh

Exactly Dodger, it's simply another rule/method of enforcing, which we can't change. And I trust the technology much more than the naked eye, especially the ability of the naked eye in real time. Even with those extra officials in the Europa league they were worse than useless sometimes!

PokerMatt

Quote from: ChrisBairdOhh on April 06, 2014, 11:41:37 AM
Exactly Dodger, it's simply another rule/method of enforcing, which we can't change. And I trust the technology much more than the naked eye, especially the ability of the naked eye in real time. Even with those extra officials in the Europa league they were worse than useless sometimes!

I think the real-time issue is key. Obviously we've stopped it and looked hundreds of times and even if we can't be 100% sure we should I suppose give the benefit of the doubt to the defending team. It's still not clear with the naked eye, but with seven cameras they are probably right.
Follow me: @mattdjourno


ChrisBairdOhh

Yes that is true I think.
Coming back to their 3.6mm error, it would be interesting to see how this is used. If the ball was measured by Hawkeye as 3.5mm over the line (i.e. A goal) it would be in their error margin. Therefore they could potentially give the defending team the benefit and award not goal. Meaning it has to be 3.7mm over the line to be awarded.

I'm NOT saying this happens. But I've no idea how they actually deal with it, knowing there is a very small error. Obviously the times that would happen are minuscule!

Fulham1959


fulhamben

Quote from: Fulham1959 on April 06, 2014, 11:58:34 AM
The line was too thick.

:005:
well heres another. the cross bar is hollow, and even if it were a solid bar it would still have some sort of bend in it over that length. is that taken into account
CHRIS MARTIN IS SO BAD,  WE NOW PRAISE HIM FOR MAKING A RUN.


Rhys Lightning 63

Can I just say at this stage, I am currently doing a dissertation on Goal Line Technology and all this 'oh the ball changed when it hit the players leg so the camera is working on a different point' or 'you do know there is a margin for error' that everyone has come up with has just been GOLD for me
@MattRhys63 - be warned, there will be a lot of nonsense

ChrisBairdOhh

Ben, not sure I understand about the crossbar issue...

And care to explain further Riether Lightning?

Rhys Lightning 63

Quote from: ChrisBairdOhh on April 06, 2014, 12:09:56 PM
Ben, not sure I understand about the crossbar issue...

And care to explain further Riether Lightning?


Well the whole premise of it is, 'When the final answer is not the final answer' - we have brought in this technology FOR THE SPECIFIC REASON to end the 'was it over the line' debate. Yet people are STILL debating it
@MattRhys63 - be warned, there will be a lot of nonsense


Artful Dodger

Quote from: PokerMatt on April 06, 2014, 11:40:43 AM
Quote from: Artful Dodger on April 06, 2014, 11:39:17 AM
I'm just glad it didn't matter in the end! And how incredible is it that the 3 games where we have been 'denied' by the technology, we have ended up winning anyway! I suppose we can be pragmatic about it on that basis and hope at some point, we benefit from what would otherwise have been a goal against us!

One of them was the WBA game I thought? Vydra's late equaliser squirmed over the line and was given on GDS.
I seem to remember that was well over the line in the scheme of things, so no real doubt about that one. We need one like yesterday not to be given to even it up!
Faber est suae quisque fortunae

ChrisBairdOhh

Quote from: Riether Lightning 63 on April 06, 2014, 12:12:10 PM
Well the whole premise of it is, 'When the final answer is not the final answer' - we have brought in this technology FOR THE SPECIFIC REASON to end the 'was it over the line' debate. Yet people are STILL debating it

Haha yes, I agree completely, and fail to understand what some users want.  However, discussing how the system works and if there are any limitations helps educate people (myself included), so we can learn about it. It's the same for anything, it is hard to accept if you don't know the process. Just look at climate change and the deniers.