Var debate 2019/20

[mancity2012_eamo]

I'm saying that if they are going to use it for offside calls then they have to be sure that VAR can make that call with an acceptable level of precision.

I suspect football will either modify VAR, or change the offside rule again.

The level of precision isn't the problem.
It's the people implementing it and the secrecy behind it.
When a ref and linesman were calling this on their own it was open to human error too, but the ref was in the immediate limelight.
He now has an invisible buffer between him and the match and the public.
Gets him off the hook, but someone is still making calls that are open to human error, or just down right corruption.

 

[mancity2012_eamo]

My impression (admittedly from TV games) is that this technology is being managed better in the USA and Europe. They don't seem to be using the bizarre Mike Riley interpretation of the new handall rules. It would be good to hear from fans abroad as to how it is working. I haven't seen any stupid "offside by one millimetre" calls in foreign games. Inter Milan got a very tight call last night in the CL which looked just level but they seemed to apply the old "attacker gets benefit of the doubt" rule.

Here they use the old, "which team does it affect again?" rule.

 

[toffee balls]

https://www.thetimes.co.uk/article/...arent-friends-with-english-referees-2wqlg3nnt

You quoted super woman.
I feel sick.

 

[James McJohn]

that's a good point, so are we saying "offside is offside" down the millimetre? but only if the technology is good enough to call it? or allowing for clear and obvious error stuff?

So, to dispell a myth - "Clear and obvious" has no relationship with the offisde whatsoever, it simply doesnt apply to offside. The point is UEFA / FIFA / PL are using the technology to the best of it's technical abilities to identify the Yes or No of an offside decision. With the agreed technology used, Sterling was offside at west ham and it was the right decision.

All a margin of error (such as the 20cm) would achieve is shift in where the measurement is done.

 

[SilverFox2]

You have to, because they are making measurements to determine whether a player is offside.

All measurements are made up to a certain level of precision. What is the precision of VAR? This is a very legitimate question to ask. The rule is that you are offside or onside, and that you can not be level. OK, that's clear, but it only works if you can make that measurement very precisely.

They need to tell the football world what that precision is in order for us to accept it.

When you make a measurement is made, you report its maximum likelihood and a confidence interval within which you can say, with say 95% probability, that the true value lies within those boundaries. From what I understand those boundaries maybe +/- several cm, and not the mm which are really what you need to make VAR work within the existing rules.

This is just a general comment on what is required to assess VAR in relation to offside. There is still the secondary issue of whether football really wants to stop the flow of the game to do this.

The ideal solution is something that is

a) precise and,
b) fast

I believe VAR is neither.

The graph below is an image I took from the Internet to demonstrate a maximum likelihood estimation and a confidence interval which enables someone to say with a confidence level of X percent (typically 95%) that my estimate of the true value of Y is Z +/- a.

a is your uncertainty. What is VAR's uncertainty? I suspect it is unworkable.

Where is the independent study of VAR technology? They've been trialing this for years. but have they analysed it properly? Maybe it has been detailed but its significance has been lost on football people?

Source: https://datumorphism.com/wiki/statistical-estimation/confidence-interval/

As we know other sports like say athletics, use slowmotion camaras to decide the winner even when competitors are going in the same direction.
Surely the possibity of 2 football athletes running in opposite directions as competitors would demand similar technology.for accuracy ?

 

[ballinio]

What it needs if fucking off. If someone can tell me how it has improved the game then i'm all ears.
Still not been to a match yet.

It needs fucking off or I won’t be back either

 

[El Mago86]

So, to dispell a myth - "Clear and obvious" has no relationship with the offisde whatsoever, it simply doesnt apply to offside. The point is UEFA / FIFA / PL are using the technology to the best of it's technical abilities to identify the Yes or No of an offside decision. With the agreed technology used, Sterling was offside at west ham and it was the right decision.

All a margin of error (such as the 20cm) would achieve is shift in where the measurement is done.

Except it wasnt the right decision because depending on the frame used he was either onside or offside. The frame used had the ball being already played. The frame prior had it just leaving the boot and sterling was onside.

 

[SilverFox2]

So, to dispell a myth - "Clear and obvious" has no relationship with the offisde whatsoever, it simply doesnt apply to offside. The point is UEFA / FIFA / PL are using the technology to the best of it's technical abilities to identify the Yes or No of an offside decision. With the agreed technology used, Sterling was offside at west ham and it was the right decision.

All a margin of error (such as the 20cm) would achieve is shift in where the measurement is done.

I think the point is that because there is a margin of error between frames unless the frame used by the var people has its immediate before and after frames also shown it is open to suspicion as to which frame has been selected.
Giving the full margin of error ie plus or minus eliminates this suspicion and need to view 3 successive frames.

 

[Tommy_Catons_Perm]

All a margin of error (such as the 20cm) would achieve is shift in where the measurement is done.

It would also give the benefit of the doubt to the attacking team. Currently a goal can be disallowed even if the attacker is not offside.
Nobody really knows for certain if a player is offside when the margin is very small. The camera lies because a player can move 13cm between frames.

If a very large margin of error of say 26 cm was used, (the diameter of a football) then it would "envelope" the distance a player can move between frames. There would be a safety factor of 2 in favour of the attacking side. Some goals which are really offside would then be allowed.

The VAR then measures 26cm as not offside. It would measure 26.00001 as offside. QED

 

[Tommy_Catons_Perm]

But really VAR wants binning. Measuring offside and tolerances and margins of error and frame rates etc. What a load of bollocks. Football and off side is not supposed to be so precise.