Calvin Plummer
Viv Anderson
Interesting study showing VAR isn't accurate enough for close decisions such as offside. After Liverpool it's no surprise...
-
All - as you will understand, the forum is exceptionally busy at this time. The admins and moderators simply don't have time to read every post in every thread. Could you PLEASE use the "Report" option below a post to flag any content that you feel we need to be aware of. We'll review everything reported as a priority and deal with it accordingly. Thank you.
VAR limitations
- Thread starter Calvin Plummer
- Start date
Statto
Free Kick Specialist
Offside is tricky enough to interpret anyway.
For a start it's when the ball is kicked when things take effect and even a split second there can have an effect when attackers and defenders are running in opposite directions.
Then you have to decide how close they have to be to be classed as on/off. It used to be that there had to be obvious daylight but now it just seems to be more that if any part of their body is ahead of the last defender they're off. Even if that's like a hand or arm which they can't play the ball with anyway.
I think the Jota one was drawn multiple times after the event by various people, it was marginal in that it depended on where you chose to start certain lines.
But if it's to "overturn obvious errors" I'm not sure it would be. It was close enough for the onfield officials to think he was either on or offside, and neither would be an error.
It's not like in tennis where the ball either clipped the line or it didn't but even then Hawkeye has a tolerance which isn't taken into account as the ball changes shape as it hits the ground, which affects the measurement of whether it's in or not. But it makes the call decisively and the players know that if Hawkeye is making the calls or they are challenging that its decision is final, unless you're Australian of mixed Greek and Indonesian heritage.
For a start it's when the ball is kicked when things take effect and even a split second there can have an effect when attackers and defenders are running in opposite directions.
Then you have to decide how close they have to be to be classed as on/off. It used to be that there had to be obvious daylight but now it just seems to be more that if any part of their body is ahead of the last defender they're off. Even if that's like a hand or arm which they can't play the ball with anyway.
I think the Jota one was drawn multiple times after the event by various people, it was marginal in that it depended on where you chose to start certain lines.
But if it's to "overturn obvious errors" I'm not sure it would be. It was close enough for the onfield officials to think he was either on or offside, and neither would be an error.
It's not like in tennis where the ball either clipped the line or it didn't but even then Hawkeye has a tolerance which isn't taken into account as the ball changes shape as it hits the ground, which affects the measurement of whether it's in or not. But it makes the call decisively and the players know that if Hawkeye is making the calls or they are challenging that its decision is final, unless you're Australian of mixed Greek and Indonesian heritage.
Redemption
Chief Eye Roller
An intersting paper.
There are some obvious things here to do with latency and perception.
Standard digital frame rates are 24fps, or one frame every 42 milliseconds.
The perceptual response time is somewhere between 30ms (elite fighter pilots) and 180ms (your average person).
So trying to get this right is a challenge just from a perceptual basic.
Then add dynamics to the ball...
A ball travelling at 50km/h can travel about .5m in between two frames at 24fps - there's a good chance that the contact is not even visible on a frame-by-frame basis.
And its easy to see how this lack o precisions still leads to human guestimation.
I suppose the question to ask is, is VAR-aided human guestimation any better than the ref trying to process it all in a split second?
MaxiRobriguez
Bob McKinlay
Let ref watch a replay from try different angles one time each. If he ain't sure either way, let goal stand.
Just get rid of the 5 minutes drawing lines and trying to pick the right frame to make it off or on depending what team it's for.
Just get rid of the 5 minutes drawing lines and trying to pick the right frame to make it off or on depending what team it's for.
Canadian_red
Grenville Morris
I'd say give the attacker the benefit in close calls every time, we want goals. The exception being if the goal is against us, because niakhaté is a frightening man and no one wants to be on his bad side.
Rzar
Bob McKinlay
I made a post saying pretty much exactly what that study says on the bit of the forum that got wiped.
It is f***ing obvious that was the case, anybody that has played any competitive shooter or game knows how important frame rates can be - and when they are measuring MM's there is zero, ZERO chance they are making the right decision.
It is f***ing obvious that was the case, anybody that has played any competitive shooter or game knows how important frame rates can be - and when they are measuring MM's there is zero, ZERO chance they are making the right decision.
Canadian_red
Grenville Morris
Depends how competitively you play your competitive shooters. It usually takes me about 300 frames to even realize someone is there.
FLC
First Team Squad
I wonder if in future there'll be a way to use the data box things that players wear as GPS devices to help with offside decisions.
I'm a complete luddite when it comes to technology so forgive me if this is bollocks.
I'm a complete luddite when it comes to technology so forgive me if this is bollocks.
Redemption
Chief Eye Roller
I work in spatial audio where we simulate how sound travels through space
at 20`C sound is travelling at 343m/s - and in audio, the standard sampling rate is 48000 samples/sec
1 sample at 48kHz is equivalent of 7mm at the speed of sound
So you can work backwards on this to understand the sampling rate need to catch the right shift in footy.
If speed of sound is 1,235 km/h. Football probably needs to be captured to understand what's happening at 30 km/h. So about 40 times as slow.
The capture device probably needs to sample at 1kHz to give you 1cm tolerance.
There are LIDAR scanners that can capture at that rate. But you probably need 3 or 4 scanners to get a full coverage.
Reconstructing the scene in near real-time would require a lot of processing power to reconstruct within a few seconds.
This will probably be what's required to go to the next level of precision.
at 20`C sound is travelling at 343m/s - and in audio, the standard sampling rate is 48000 samples/sec
1 sample at 48kHz is equivalent of 7mm at the speed of sound
So you can work backwards on this to understand the sampling rate need to catch the right shift in footy.
If speed of sound is 1,235 km/h. Football probably needs to be captured to understand what's happening at 30 km/h. So about 40 times as slow.
The capture device probably needs to sample at 1kHz to give you 1cm tolerance.
There are LIDAR scanners that can capture at that rate. But you probably need 3 or 4 scanners to get a full coverage.
Reconstructing the scene in near real-time would require a lot of processing power to reconstruct within a few seconds.
This will probably be what's required to go to the next level of precision.
Redemption
Chief Eye Roller
not with GPS - it has an error of +/- 3m.... good enough for tracking over time, but not at the level precision.
This is pretty much coming in the form of semi-automated offside, large numbers of cameras and sensors able to flag to the VAR whenever a player in an offside position receives the ball.
/cloudfront-us-east-2.images.arcpublishing.com/reuters/6KCJD2ATEBIRHHAHRBRHQ7TOSQ.jpg)
Semi-automated offside technology approved by FIFA for 2022 World Cup
Semi-automated offside technology will be used at this year's World Cup, promising decisions that are more accurate and a lot quicker, world soccer's governing body FIFA said on Friday.
Quntib Hollox
Jack Armstrong
The grey area with offsides for me is do they freeze it when ball first makes contact with the boot or when it leaves?
Redemption
Chief Eye Roller
there's more technica detail here of the robot offside
www.fifa.com
Semi-automated offside technology to be used at FIFA World Cup 2022™
FIFA has announced that semi-automated offside technology will be used at the FIFA World Cup 2022™ in Qatar starting on 21 November.
www.fifa.com
Calvin Plummer
Viv Anderson
What3words is the solution
How about changing the offside rule.
Draw a line across the pitch e.g. 25 yards out .
Ball must cross the line before attacker.
"Reset" when the ball crosses that line the other way. (Not unlike ice hockey)
The linesman can then stand in 1 place looking fixedly along a line that doesn't move.
Piece of piss for automatic cameras too.
Draw a line across the pitch e.g. 25 yards out .
Ball must cross the line before attacker.
"Reset" when the ball crosses that line the other way. (Not unlike ice hockey)
The linesman can then stand in 1 place looking fixedly along a line that doesn't move.
Piece of piss for automatic cameras too.
adam09
Super Koopa
It just needs to be a significant part of the attacker is past the defender = offside. Not a few cms of toe, head, knee etc.
Sure they said last season that the extremely close ones they would class as onside, yet they seemingly didn't do that.
Sure they said last season that the extremely close ones they would class as onside, yet they seemingly didn't do that.
Barry
Where's me hammer?
Just make it if you are level you are on. Easy
Sent from my SM-A217F using Tapatalk
Sent from my SM-A217F using Tapatalk
Templeton
First Team Squad
For me they should just simplify it down and just look at where the feet are. Forget about armpits and knees and whatever else and just go by the feet.
Huxley
John Robertson
I’d not be against a ‘margin of error’ ruling past which would be offside. But the benefit of doubt given to those stupid his left toe is past the line decisions.
Redemption
Chief Eye Roller
It should be half a stride or more, because you have to be moving to get the advantage.
Morpeth
John Robertson
Pretty sure that’s what it always was before they started f***ing around with things.
VAR should just be binned off, end of story. Anything static like ball over the line can use Hawkeye or similar, but other than that football and technology doesn’t work. It’s been tried loads now and it’s just a pain in the arse and everyone discusses it in the same way as they did when it was just a ref.
Ultimately, nearly everything is a judgement anyway (or technically impossible to implement) so I honestly have no idea why we bother.
Just because certain technologies exist does not mean they should be used.
No one can make me change my mind on this either, no matter what improvements they think will help. Utter wank.
Morpeth
John Robertson
This is the entire problem. Everyone tries to make offside better and easier to understand but if you’re talking about margin of error then where does the margin start. You need margins for margins.
IT’S SHIT and everyone knows it.
Statto
Free Kick Specialist
Why not go back to clear daylight = offside and anything less is on? It always made more sense that way anyway.
Morpeth
John Robertson
That’s just a variation on a theme. It doesn’t make a jot of difference where you define the line.
It's not difficult to resolve things.
Change the wording of the laws to 'If in the opinion of the referee (or linesman)....
Then we can dispense with the VAR farce completely.
But keep the cameras so that any official consistently getting it wrong can be removed from the list, and any player caught diving of feigning anything whatsoever is given an instant 5 match ban and a 3 match ban against the team where they cheated, with the club deducted any points gained from the game.
It will stop the diving and cheating immediately and eventually drag up the standard of refereeing.
It won't happen though. Too many vested interests. All down to money.
Change the wording of the laws to 'If in the opinion of the referee (or linesman)....
Then we can dispense with the VAR farce completely.
But keep the cameras so that any official consistently getting it wrong can be removed from the list, and any player caught diving of feigning anything whatsoever is given an instant 5 match ban and a 3 match ban against the team where they cheated, with the club deducted any points gained from the game.
It will stop the diving and cheating immediately and eventually drag up the standard of refereeing.
It won't happen though. Too many vested interests. All down to money.