VAR (PL introduction 2019)

[Henkeman]

You don't need 22 players, you're over-complicating it. You need the deepest outfield player on each side, a wide field lens and as high a frame rate as possible. The tracking part is easy.

No, you're over-simplifying it. You need to be able to track in three dimensions otherwise it's impossible to judge whether it is entirely in line or not. That's precisely the reason you need so many cameras for goal line technology which in principle is just about one fixed line, and they then need calibrating.

Just the ball tracking for cricket or tennis too needs multiple cameras calibrated to follow that, which don't always pick up properly, and which cannot operate outside their narrow field. This is why you can't use Hawkeye to work out low catches after taking the edge, even though it nominally should be tracking the ball path.

If you want to advocate a camera following the line of the last defender, that's fine. But it doesn't help because it can't possibly do anything other than follow.

 

[burning blue soul]

You don't need 22 players, you're over-complicating it. You need the deepest outfield player on each side, a wide field lens and as high a frame rate as possible. The tracking part is easy.

you cant have a tracking camera, at least at low level. there are other variables to consider, the players warming up, managers, 4th official, physios and injured players getting in the way of the camera. it has to be high up and linked to the ball being kicked and the sensor on the forward players body.

 

[aguero93:20]

No, you're over-simplifying it. You need to be able to track in three dimensions otherwise it's impossible to judge whether it is entirely in line or not. That's precisely the reason you need so many cameras for goal line technology which in principle is just about one fixed line, and they then need calibrating.

Just the ball tracking for cricket or tennis too needs multiple cameras calibrated to follow that, which don't always pick up properly, and which cannot operate outside their narrow field. This is why you can't use Hawkeye to work out low catches after taking the edge, even though it nominally should be tracking the ball path.

If you want to advocate a camera following the line of the last defender, that's fine. But it doesn't help because it can't possibly do anything other than follow.

Why do you need to track in 3 dimensions to make a decision based on one axis? If the camera is dead in line on width, it doesn't need to worry about height or depth.
If you have a still, dead in line with the last defender, on a high enough frame rate to capture the exact moment the pass is played, then you have the perfect picture for the VAR or on field referee to make a call. Problem solved. Goal line technology needs to automatically inform the referee as soon as the ball crosses the line, this just needs to track the offside line to result in a simpler and more accurate decision for the human official.

 

[aguero93:20]

you cant have a tracking camera, at least at low level. there are other variables to consider, the players warming up, managers, 4th official, physios and injured players getting in the way of the camera. it has to be high up and linked to the ball being kicked and the sensor on the forward players body.

I'm aware of that mate, it should be on a high rail. It doesn't need to be linked to the ball being kicked though, it needs to be recording video constantly at as high a frame rate as possible on a wide lens and linked to a sensor on the last defender to keep it on the correct point of the rail.

 

[Henkeman]

Why do you need to track in 3 dimensions to make a decision based on one axis? If the camera is dead in line on width, it doesn't need to worry about height or depth.
If you have a still, dead in line with the last defender, on a high enough frame rate to capture the exact moment the pass is played, then you have the perfect picture for the VAR or on field referee to make a call. Problem solved. Goal line technology needs to automatically inform the referee as soon as the ball crosses the line, this just needs to track the offside line to result in a simpler and more accurate decision for the human official.

Because it is impossible for technology to remain level in all instances. It can only respond to movement and is necessarily behind it. By definition, it will not be in that axis, it will be slightly to one side or the other. These things are far more complex than they might initially appear, which is why you don't just have two cameras on the inside of a goal post looking across - which is the equivalent concept.

 

[aguero93:20]

Because it is impossible for technology to remain level in all instances. It can only respond to movement and is necessarily behind it. By definition, it will not be in that axis, it will be slightly to one side or the other. These things are far more complex than they might initially appear, which is why you don't just have two cameras on the inside of a goal post looking across - which is the equivalent concept.

These rail cameras can track bullets over a kilometre when custom made mate, they won't have any problem keeping level with a backtracking centre half. As already said, they're there to grab a still picture, not to make a decision and would need nothing on the scale of GLT which needs to make an instantaneous decision across every millimetre of a 3D shape. Bringing these in would result in far, far more accuracy than the current camera system.

 

[Henkeman]

These rail cameras can track bullets over a kilometre when custom made mate, they won't have any problem keeping level with a backtracking centre half. As already said, they're there to grab a still picture, not to make a decision and would need nothing on the scale of GLT which needs to make an instantaneous decision across every millimetre of a 3D shape. Bringing these in would result in far, far more accuracy than the current camera system.

It's not about tracking. It's about the need to be side on all the time which is a logical and scientific impossibility. The only way you could do that would be multiple tracking cameras a la Hawkeye, but over an enormous area and trying to track all players plus the ball.

This is why it's vastly more complex than you are claiming, and exactly why I'm saying that you need all those cameras just for goal line technology. They don't refuse to just have those two cameras in the goalposts for a giggle, but because proper tracking needs multiple points of origin.

Same reason you have anything between 8 and 16 cameras for cricket ball tracking. The fewer you have, the less accurate it is.

 

[aguero93:20]

It's not about tracking. It's about the need to be side on all the time which is a logical and scientific impossibility. The only way you could do that would be multiple tracking cameras a la Hawkeye, but over an enormous area and trying to track all players plus the ball.

This is why it's vastly more complex than you are claiming, and exactly why I'm saying that you need all those cameras just for goal line technology. They don't refuse to just have those two cameras in the goalposts for a giggle, but because proper tracking needs multiple points of origin.

Same reason you have anything between 8 and 16 cameras for cricket ball tracking. The fewer you have, the less accurate it is.

You're tracking across 360° in cricket, not from left to right. We're literally working across one axis with offside. One.

 

[Henkeman]

You're tracking across 360° in cricket, not from left to right. We're literally working across one axis with offside. One.

No, you aren't. Because the time the ball is passed is essential to that for one thing, so focusing on one line is only half the story. And secondly, it is a scientific impossibility for technology to be perfectly side on all the time - that immediately means it has to be tracked in three dimensions to account for the inevitable offset.

If you have a device that can anticipate the movements of sentient beings perfectly and not react to what they do (and thus be behind) then NASA would love to hear from you.

 

[aguero93:20]

No, you aren't. Because the time the ball is passed is essential to that for one thing, so focusing on one line is only half the story. And secondly, it is a scientific impossibility for technology to be perfectly side on all the time - that immediately means it has to be tracked in three dimensions to account for the inevitable offset.

If you have a device that can anticipate the movements of sentient beings perfectly and not react to what they do (and thus be behind) then NASA would love to hear from you.

As I've already said mate, you don't need to track the ball if you have as wide angle a lens as possible and as high a frame rate as possible. Neither do you need to anticipate when you're tracking across one axis at multiple times the speed.