VAR thread 2022/23

[Trevor Morley's Tache]

Agreed that this is a sensible move but the dubious aspect is where he talks about 'once the ball release frame has been agreed' 'it is locked in'. Previous articles have shown a +/-3 frame (at 50 frames a second) possibility. These new guidelines do not build in any margin of era for that subjective choice. Assuming a player is moving in one direction at 12 seconds per 100m (quite slow sprint) that equates to 16 cm + or - for each 3 frame margin (32cm over all = 1ft if defender and attacker moving at samespeed in opposite directions. )
Now show that tolerance in the lines and VAR begins to look rediculous. Faster frame rates will help. Be interesting to see if semi automated works. Either way, it is plainly wrong for the article to state Offsides are now a 'fact'.

Unless optical sensor technology improves massively I think 50fps is about the limit for football.

 

[halfcenturyup]

You missed the point the possibility has been discussed for sometime, while it remains on the agenda and will likely be implemented in the next few seasons IFAB have to consult all the federations before they implement changes

Tbh, I can only go by what is available publicly, and, other than a few throw away comments worrying about playing time, there has been nothing on the IFAB agendas about this.

Edit: I would have thought a change like this would be complicated to implement consistently at all levels, which is maybe why it hasn't been implemented after 5 years even though some other 2017 proposals have been.

 

[Cheer Up Peter Reid]

It seems simple to me, remove the human element and replace it with some form of automated decision making. Whether it's based on some kind of tracking system, sensors, whatever, I don't care, just remove the element of human judgement/error/cheating. I can accept an incorrect decision made by an autonomous machine.

 

[bluenova]

Interesting read.

The IMU sensor inside the ball gives the precise moment a ball is kicked, but the position of the player is still only sampled at the camera frame rate which is 50fps. so there is still a potential for a large +/- error which is dependant on the speed of the attacker relative to the speed of the defenders. The position of the ball is more accurate than the position of the player by a factor of 10, and AI can only go so far in filling in the missing information.

Useful, but still limited by the camera frame rate. At least they can no longer chose a frame where they 'think' the ball was passed to manipulate the outcome, unless they have the ability to override the system.

All of this is still dependent on transparency and oversight. It's no good them doing this behind closed doors where there is no scrutiny because they could claim anything and nobody would be any wiser. And what happens when the IMU fails, or falls out of calibration? We'd be back to guessing when the pass took place. But do you think they'd tell us, or would they just pretend everything was fine like the PL did for the Dipper's game?

In theory it should be able to work out almost exact positions.

At the moment, you're stuck with frame rate, and having to choose between two frames, guessing which is the best. Even if the computer was assuming steady motion between each frame, then it would clearly be more accurate - after all the biggest margin of error is based on a runner at full speed, and those movements are going to the most predictable and smooth. The ones where the player is moving slowly or changing direction will be more complex, but of course already have a much smaller margin of error.

However AI should be much cleverer than assuming steady motion. It's not as if we're watching 22 Ian Curtis's jerking about randomly across the pitch. We're watching people who will speed up and slow down over multiple frames, who will be making relatively infrequent and fairly predictable changes in direction (infrequent in that they won't change direction multiple times a second, and predictable to a computer in hindsight).

Every movement in your body is signalled by movements elsewhere in the body - so if the AI has data from all over the body, it can predict what's expected to happen to other parts of the body. If you're going to change direction, or set off on a run, or make a feint, then different small movements all over your body will signal that, and a computer that's watched a million players doing exactly the same motion will be able to predict what happens next pretty accurately.

 

[Dave Ewing's Back 'eader]

It seems simple to me, remove the human element and replace it with some form of automated decision making. Whether it's based on some kind of tracking system, sensors, whatever, I don't care, just remove the element of human judgement/error/cheating. I can accept an incorrect decision made by an autonomous machine.

I have no trouble with the 'autonomous' machines currently used in other sports. There never seems to be any lingering and festering post-decision discussion as to whether a ball has been wrongly called in tennis, or the trajectory that delivers an lbw was incorrect, and there never seems to be ructions on the terraces when a decision in rugby is called as being 'inconclusive'! Football administrators and governors have to come up with summat that appears to be full of holes and objections.

 

[Gorton_Tubster]

It seems simple to me, remove the human element and replace it with some form of automated decision making. Whether it's based on some kind of tracking system, sensors, whatever, I don't care, just remove the element of human judgement/error/cheating. I can accept an incorrect decision made by an autonomous machine.

What for? Are yuou talking handballs? Or offside? Surely not fouls?

 

[bluenova]

Agreed that this is a sensible move but the dubious aspect is where he talks about 'once the ball release frame has been agreed' 'it is locked in'. Previous articles have shown a +/-3 frame (at 50 frames a second) possibility. These new guidelines do not build in any margin of era for that subjective choice. Assuming a player is moving in one direction at 12 seconds per 100m (quite slow sprint) that equates to 16 cm + or - for each 3 frame margin (32cm over all = 1ft if defender and attacker moving at samespeed in opposite directions. )
Now show that tolerance in the lines and VAR begins to look rediculous. Faster frame rates will help. Be interesting to see if semi automated works. Either way, it is plainly wrong for the article to state Offsides are now a 'fact'.

There is almost certainly a political compromise to it.

We've seen the fuss over the Rashford decision, when, if you know the way the frame rates work, any argument over him being slightly offside/onside is pointless. There may be much worse decisions that appear fine, simply because the camera got a shot at the wrong time.

Offsides weren't 100% fact now, won't be 100% with semi-automated, and definitely weren't with humans and flags. Ultimately, anything that's better than the human who can make massive mistakes, or miss a touch of a second player, is fine with me.

 

[Trevor Morley's Tache]

In theory it should be able to work out almost exact positions.

At the moment, you're stuck with frame rate, and having to choose between two frames, guessing which is the best. Even if the computer was assuming steady motion between each frame, then it would clearly be more accurate - after all the biggest margin of error is based on a runner at full speed, and those movements are going to the most predictable and smooth. The ones where the player is moving slowly or changing direction will be more complex, but of course already have a much smaller margin of error.

However AI should be much cleverer than assuming steady motion. It's not as if we're watching 22 Ian Curtis's jerking about randomly across the pitch. We're watching people who will speed up and slow down over multiple frames, who will be making relatively infrequent and fairly predictable changes in direction (infrequent in that they won't change direction multiple times a second, and predictable to a computer in hindsight).

Every movement in your body is signalled by movements elsewhere in the body - so if the AI has data from all over the body, it can predict what's expected to happen to other parts of the body. If you're going to change direction, or set off on a run, or make a feint, then different small movements all over your body will signal that, and a computer that's watched a million players doing exactly the same motion will be able to predict what happens next pretty accurately.

Oh, I've no doubt it should be more accurate but there will still be a margin of error, but at least all decisions will be measured within 1/500th of a second so there will be consistency between measurements. However, there is still the issue of transparency/scrutiny in the application of the system and whether it can be overridden or otherwise interfered with without anyone knowing.

That for me is the biggest problem.

 

[jjctid]

Worth a read for anyone thinking Rashford was offside and a sensible change to the way VAR views close offside calls.

RE this "tolerance" amendment - I have asked around about it and I have not found one person who knew about it. Personally the rashford goal was the first time I have heard it mentioned - make of that what you want.

 

[bluenova]

Oh, I've no doubt it should be more accurate but there will still be a margin of error, but at least all decisions will be measured within 1/500th of a second so there will be consistency between measurements. However, there is still the issue of transparency/scrutiny in the application of the system and whether it can be overridden or otherwise interfered with without anyone knowing.

That for me is the biggest problem.

I don't think there's human input into the actual decision. They can't choose to move a line, or make a decision on when the ball is moved.

I'm not a conspiracy theorist, but do believe that bias (mostly unconscious) could affect decisions where the human has some control. To change this it would involve seeing a decision on screen and then not passing that on to the ref. That's an active decision clearly made in front of everyone with access to the feed, all the techs involved, everyone sitting in the VAR room, and would involve justifying after the match why no decision was made. That just isn't realistically going to happen.