Var debate 2019/20

[spiny]

I'm sorry mate but my white line IS parallel with the penalty box. I've measured it. It shows Salah's knee as being maybe 6 inches on side. Rammy makes a good point about the height of Salah's knee, compared to Stones' foot which is on the ground.

However, there is no line that can be correctly painted on this screen which shows Salahs knee to be beyond it. If it does, the line is drawn wrong, period.

There is a job waiting for you at Stockley Park.

 

[TheRemainsOfTheDave]

Not really. Someone said I should have drawn the white line parallel to the penalty box on screen. I was merely demonstrating how daft that is.

The white line I have drawn IS parallel to the penalty box in real life. That is what matters. It is correct.

You need to read my post from a couple of pages back. It is IMPOSSIBLE to grab screen frames and apply any form of reliable geometrical rules to determine an accuracy of millimetres ...

You cannot use any reference on the pitch because the accuracy of the lines and grass cuts are not checked by the officials before the game. Secondly the angle of the camera needs to take into effect perspective in all 3 planes, the "width" of a band of grass will narrow in the z-plane when looking directly behind it but will also be affected when looking slightly to the side in the x-plane and when looking from above in the y-plane, therefore rendering attempts to measure proportions of the grass band forward and behind a player inconsistent. Thirdly, all this only works with a completely flat & totally level pitch. Finally the image is not of sufficient resolution to make such a measurement.

The decision should be made using the technology developed to judge such matters as this is then consistent for each team and each game. The fact that there are no VAR images suggests it wasn't working and therefore the game has a major problem because some teams are getting decisions in their favour and others are not being given that opportunity. The fact that this has not yet been disclosed further suggests a cover up that the technology is not fit for purpose and we should return to the previous system immediately. The clubs affected need to start legal proceedings to force the matter.

I studied Geometrical and Engineering Drawing to a high level and it is too complex to use a single 2D image as the starting point.

The first question that needs answering is whether the lines on the pitch are measured and checked for accuracy. Using grass lines as a reference point is ridiculous to the extreme as these are not official pitch markings.

 

[Father Paul]

I'm sorry mate but my white line IS parallel with the penalty box. I've measured it. It shows Salah's knee as being maybe 6 inches on side. Rammy makes a good point about the height of Salah's knee, compared to Stones' foot which is on the ground.

However, there is no line that can be correctly painted on this screen which shows Salahs knee to be beyond it. If it does, the line is drawn wrong, period.

I'm not entirely convinced by your argument or those saying it was offside but the most important thing surely is to find out if and why VAR decided within 20 seconds that it was a good goal. Confidence in this system has been shattered imo and matters are only going to go from bad to worse in the weeks and months ahead if this continues.

 

[gordondaviesmoustache]

Personally I would question whether it’s worth it though, particularly taking into account the detrimental impact to the match going fan. To me, if you can’t see a player is offside without the need to put the lines across, then I would go with the benefit of the attacker - I don’t see it as enough of an advantage to require it to be such an absolute.

I do think people have forgotten the underlying intent of the laws at times, which for offside is to stop the attacker getting an unfair advantage. If their knee or foot is just offside, I still think the main reason for teams scoring is still either good attacking play or poor defending, not that the minutest bit of their body might be offside.

Your view appears to be predicated on the basis that glaring errors (or worse) aren't made in relation to offside - think of Walker for Spurs v us a few years ago.

I think offside (there or thereabouts) falls into the same category as whether the ball has crossed the line; no-one is sensibly suggesting returning to a situation where that is determined on the pitch. The reason for this is the proliferation of cameras in stadiums which mean that an incorrect call (eg Frank Lampard) can definitively be exposed as such by tv, rather than being subject to some form of subjectivity, like a handball or a foul.

I draw that distinction and in those circumstances if the technology is there to get a binary choice correct then it should be deployed imo.

 

[alexmcity]

Thanks to all people trying to establish the truth via measurments on screen pictures, but these efforts are amateurish. If it was easy, we wouldn't need advanced technology in the first place.

 

[TheRemainsOfTheDave]

Inconclusive. You can't determine from that image where Salah's knee is in relation to the reference line. I know it appears to be behind it, but it may actually be in advance of the line because of the effect of angle and perspective. See the photo below where Stones clears the ball when its above but not over the line. THe ball appears to be behind the line because we are viewing it from an angle, but when viewed in the plane of the crossbar and goalline it was not.

This is why I believe these VAR measurements are floored. There is no adjustment for this effect.

It IS possible but I am unsure if VAR is developed correctly. For goal line technology, perspective does not come into it. You just need to be level with the goal line and can view it side on, above and all angles between and the position of the ball to the line will be consistent. With VAR there is no line. It is artificially created by (I assume) reference marking points on the pitch. If the pitch markings are out, it fails. If the pitch slopes, it fails. Loads of reasons.

 

[aka blue jambo]

So was VAR working on Sunday or not?

 

[TheRemainsOfTheDave]

So was VAR working on Sunday or not?

Think it was on a 10-minute coffee break.

 

[Marvin]

It IS possible but I am unsure if VAR is developed correctly. For goal line technology, perspective does not come into it. You just need to be level with the goal line and can view it side on, above and all angles between and the position of the ball to the line will be consistent. With VAR there is no line. It is artificially created by (I assume) reference marking points on the pitch. If the pitch markings are out, it fails. If the pitch slopes, it fails. Loads of reasons.

I have been suggesting this point for ages. If you don't adjust for perspective, the image is illusory.

There is a temporary solution that they could so and make the reference body part the foot but even that would fall down if the foot was at different heights from the pitch.

I have never once seen a VAR image that they occasionally upload that has ever been adjusted for this effect so I doubt they are doing it. The public would not understand if they did it, and the referees are probably totally clueless as to the issues. Thinking in 3D is very difficult and most people never do it.

 

[spiny]

I have been suggesting this point for ages. If you don't adjust for perspective, the image is illusory.

There is a temporary solution that they could so and make the reference body part the foot but even that would fall down if the foot was at different heights from the pitch.

I have never once seen a VAR image that they occasionally upload that has ever been adjusted for this effect so I doubt they are doing it. The public would not understand if they did it, and the referees are probably totally clueless as to the issues. Thinking in 3D is very difficult and most people never do it.

Plus pitches are not flat. They are all curved so 2D lines are inherently wrong.