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The Real Buh

Daily reminder that Pukki was Onside

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17 hours ago, Surfer said:

That is a rubbish answer. They are using video cameras which image at 50 frames per second. So if we assume the exposure time is 1/50th of second the light is being captured for a full 1/50th of a second. On a pass like Vrancic made the ball is traveling at what 40 feet per second initially? If so, a ball travel distance of over 9 inches is all blurred together into that frame. So let's reduce the exposure time to 1/00th sec, that is better because now the ball travel distance blurred together is now less than 5 inches, unfortunately the other 1/50th sec isn't being captured at all... so no you really can't freeze the image "at the point of contact" - that is an absolute lie. 

This is clearly correct: the technology is being used as if it had a degree of precision which exceeded its fundamental resolution which, in any form of measurement, is a schoolboy error.

Leaving aside the matter of aperture time, the frame rate of the EPL VAR technology (according to the Premier League's own website) is 50 frames/s, so the time resolution is 0.02s. This means that the first frame which shows the ball having left the passer's foot could be 0.02s after it actually left it (or more, in practice).


The fly-in sprint speed of a male athlete is generally considered to be in the 8-12m/s range, so let's say 10m/s, so the same frame could show the striker in a position corresponding to 0.02s after the ball was kicked (assuming the cameras are precisely synchronised compared to the frame rate).

So
* The maximum error between the striker's 'actual' position and that shown in the frame could therefore be 10m/s x 0.02s, or 20cm.
* An out-rushing defender could, of course, be shown 20cm too far away from goal.
* The all-important postures of the players (e.g. arm position) could have changed hugely during the error period.
*The human identification of the 'nearest' frame is also subject to error.
* It isn't possible accurately to assess player positions vs parallel lines without individual 'in-line' cameras.
I could go on.
All of which makes the infinitessimal study of the VAR's carefully tweaked lines (which are treated as gospel) somewhat ridiculous.

Btw, in perusing the Premier League's website to check the VAR frame rate, I was amused to read all about VAR and how it will be implemented. It contains such nonsensical gems as: "The broadcast cameras operate with 50 frames per second, so the point of contact with the ball is one of those frames inside the 50 per second."  In particular, there is much comedy gold to be found in the discussion of 'clear and obvious errors'.

But, be all this as it may, Pukki was onside!

If only we could get the genie back in the bottle!  Whoever would have guessed that VAR would make it EASIER to favour the preferred outcome?

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3 minutes ago, paul moy said:

Well, I want out of the cheating Premier League. 

Your wish is Delias command. Unfortunately. 

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4 minutes ago, The Real Buh said:

TEE-MU PUKKI

TEE-MU PUKKI

TEE-MU PUKKI WAS ONSIDE!

TEE-MU PUKKI WAS ONSIDE!

 

I like that one!

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10 minutes ago, The Real Buh said:

TEE-MU PUKKI

TEE-MU PUKKI

TEE-MU PUKKI WAS ONSIDE!

TEE-MU PUKKI WAS ONSIDE!

 

Is that to the tune of Bread of Heaven? Fits perfectly!

 

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33 minutes ago, El Convento said:

If only we could get the genie back in the bottle!  Whoever would have guessed that VAR would make it EASIER to favour the preferred outcome

And this is exactly the issue, which we understand as possible receivers of poor decisions compared to the average big team.

You would think better teams, scoring more goals, would probably have an incrementally increased amount of VAR decisions against them. Appears not, in the main.

Now a days, instead of handing a decision to the team with more clout as an on field ref (which would mean you have to ride the wave of anger from the stands), chummy can do it for you 100 miles away. Happy days.

 

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On 30/12/2019 at 11:48, Feedthewolf said:

As far as I know, the ACN/BEN guys have to have all the banners checked by someone at the club before they're allowed to use them. Would be interested to know if the club 'okayed' the use of the 'CLEARLY AND OBVIOUSLY NOT WORKING' banner that appeared in the Barclay on Saturday... can't imagine they would have sanctioned it?

You wouldn’t be surprised if the club kept an eye open for that banner and told them not to display it again would you ? Will be interesting to see if it reappears tomorrow 

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3 hours ago, El Convento said:

This is clearly correct: the technology is being used as if it had a degree of precision which exceeded its fundamental resolution which, in any form of measurement, is a schoolboy error.

Leaving aside the matter of aperture time, the frame rate of the EPL VAR technology (according to the Premier League's own website) is 50 frames/s, so the time resolution is 0.02s. This means that the first frame which shows the ball having left the passer's foot could be 0.02s after it actually left it (or more, in practice).


The fly-in sprint speed of a male athlete is generally considered to be in the 8-12m/s range, so let's say 10m/s, so the same frame could show the striker in a position corresponding to 0.02s after the ball was kicked (assuming the cameras are precisely synchronised compared to the frame rate).

So
* The maximum error between the striker's 'actual' position and that shown in the frame could therefore be 10m/s x 0.02s, or 20cm.
* An out-rushing defender could, of course, be shown 20cm too far away from goal.
* The all-important postures of the players (e.g. arm position) could have changed hugely during the error period.
*The human identification of the 'nearest' frame is also subject to error.
* It isn't possible accurately to assess player positions vs parallel lines without individual 'in-line' cameras.
I could go on.
All of which makes the infinitessimal study of the VAR's carefully tweaked lines (which are treated as gospel) somewhat ridiculous.

Btw, in perusing the Premier League's website to check the VAR frame rate, I was amused to read all about VAR and how it will be implemented. It contains such nonsensical gems as: "The broadcast cameras operate with 50 frames per second, so the point of contact with the ball is one of those frames inside the 50 per second."  In particular, there is much comedy gold to be found in the discussion of 'clear and obvious errors'.

But, be all this as it may, Pukki was onside!

If only we could get the genie back in the bottle!  Whoever would have guessed that VAR would make it EASIER to favour the preferred outcome?

Another good explanation: bottom line is if the  defender and attacker are standing still the current technology can work for its intended purpose, but at typical speeds of movement it can’t. If they are waiting for the frame of video AFTER the ball has been contacted to make the analysis the time error would be between 0.02 and 0.04 sec after the ball was struck - so an average of 30 cm now on your calculations.... btw typically broadcast camera are synced to the start of the frame time, but they often don’t image for the entire frame time, so there are obviously gaps in the data when that happens. I’m also assuming the cameras are progressive scan and not interlaced as that’s a whole other set of blur and loss of resolution issues that affect the ability to decide where the body is. 
 

As Ricardo has said - just trust the ref and his assistants for offside, and / or bring the ref’s attention to a problem and have him review it on a monitor - it worked fine in the World Cup

Edited by Surfer

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