A&H

VAR Wobbly Lines

JH

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Remember the whole wobbly lines thing in the Huddersfield - Man United game?

It seems that system has been scrapped, or at least replaced for the World Cup:

 
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Its good to see they are investing in the technology to improve accuracy. The video is about the vertical dimension (which is new for the virtual offside line).

I'd be interested to see how accurate the line on the ground is. The number of offside decisions made based on very small margins is far more than the GLT very small margin decisions so by comparison the virtual offside line must be more accurate I doubt this is the case given the margin of error for Hawkeye GLT is 5mm.

The other question is what happens if the virtual goal line shows an attacker to be offside (or vice verse) but the distance is within the margin of error. Would they still go with the virtual goal line on that incident knowing it could be wrong?

Non of this is in the protocol but it should be. In addition all of this should have been developed, tried and proven before the biggest even of the game. I know from a reliable source HAL (Aus) does not use virtual goal line.
 
I’ve said a few times that VAR could work in some form done right, it has to be almost immediate, understandable and trustworthy to its paying customers, not only to TV but in the crowd too. This system looks swish but I’d like to see it tested at some rubbish level before failing miserably at the biggest stage of all...
 
One more thing I am not satisfied with is the frame they check offside with. If correct technology is not used it could have a big impact on the correctness of the decision in tight calls. Basically if dedicated technology is not used, VAR decision can be just as inaccurate as an AR on tight calls because the frame used for the decision is not the exact moment offside should be decided but the closest frame available to it.

Bear with me for a bit of maths here if you want proof.

The standard camera/playback frame rate is 24 or 30 fps. At the better frame rate there is 1/30th of a second between the two frames that a VAR can look at the incident.

At elite level the top speed of footballers is about 40km/h. If an attacker is running towards the goal and the second last defender in the opposite direction to put him offside, its not uncommon to have a relative speed of more than 50km/h. This means the relative movement between the two frames (1/30 of second) is 46cm. This is a large gap. There is no way VAR can make a definitive decision based on that.

Another way of looking at it is the length of time the ball is in contact with a foot at a kick is just over 0.01 seconds (yes i did a bit of research for this). This means there is a two in three chance no frame actually catches any contact with the ball in a kick.
 
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which is why expecting VAR to work without investment in appropriate technologies is ridiculous! this looks like an excellent system but using it with current technology and frame rates is asking for trouble
 
So have they figured out how to get the line to consider body parts other than the feet? That's always been a problem with the virtual line shown on TV by commentators - it can't be used to compare feet to torso/chest/shoulder. That, and while an AR may be able to spot it to within inches, you can't see that closely on the screen
 
Really sad in some ways that technology takes over something that sells newspapers and clogs up fans and refs forums. What are we all going to argue about now!
 
Really sad in some ways that technology takes over something that sells newspapers and clogs up fans and refs forums. What are we all going to argue about now!
Don't worry. VAR has caused more arguments that it's solved in Australia!
Although it tickles me to read that they're expanding the scope of VAR in the WC. It's going to be a clustertruck of the highest order. I'll bring the popcorn!!
 
The standard camera/playback frame rate is 24 or 30 fps. At the better frame rate there is 1/30th of a second between the two frames that a VAR can look at the incident

All the cameras record at a minimum of 300 fps. That's how the slow motion replays look smooth instead of jerky like they used to when I was a kid.

Usain Bolt's fastest speed was 44.7s km/h, or 12.4 m/s. That's 4 centimetres per frame. I think that's good enough.
 
All the cameras record at a minimum of 300 fps. That's how the slow motion replays look smooth instead of jerky like they used to when I was a kid.

Usain Bolt's fastest speed was 44.7s km/h, or 12.4 m/s. That's 4 centimetres per frame. I think that's good enough.
There is a lot more to it than that. While most cameras are capable of shooting higher frame rate, they don't shoot that fast because you have to compromise some other quality (resolution, sharpness...) for higher frame rate. That's why when you freeze frame you never see the shape of the ball or the exact position of the leg (again there is more to it there as well). These cameras are for broadcasting purposes and they wont over capitalise on their equipment to satisfy VAR requirements. The only exception is the goal line camera used for GLT (when in use). But there is only one at each end.

There is also the capability of your video software (player)/display and anything in between (transmission, etc). A chain is only as strong as its weakest link.
 
Two dedicated offside cameras are better than none I guess 😁
They seem to have been investing a fair bit to make sure VAR is a success at the World Cup which is a positive step. But as you say, I am not sure if we are going to see the same sort of investment at lower levels.
 
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That looks like an amazing implementation, rather high-tech. A lot of time and money must have been spent developing this. I look forward to seeing this aspect of the implementation
 
That looks like an amazing implementation, rather high-tech. A lot of time and money must have been spent developing this. I look forward to seeing this aspect of the implementation

Be careful. Some around here won't be happy to hear positive things said about the VAR system. :)
 
There was a small earthquake last night in Hull, I'm not sure if it was actually geological or just @Mintyref dropping his wallet! :smoke:

12.7m/s!!!! Thats the equivalent of running a mile in 2 minutes & 9 seconds!! ;):angel:
 
I'm in Cottingham in the morning, I'll pop in and see if the new Motability ramp has survived the shift in tectonic plates!
 
Folks, again, please stop taking threads off topic. It isn't acceptable and annoys other members (they have told us). If you want to have a private chat then please use the forum function designed exactly for that.
 
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