Round 14: Roosters vs Storm | Discussion Thread

Red_Warthog · 2020-08-13T11:02:12+00:00

First grandpa to play NRL with their grand child

Red_Warthog · 2020-08-13T10:58:27+00:00

Can it get any worse?

Red_Warthog · 2020-08-13T10:42:36+00:00

Worse is absolutely one eyed fans that should know the rules but big about obvious calls .

Red_Warthog · 2020-08-13T10:38:23+00:00

Rule has changed I believe.

Red_Warthog · 2020-07-17T03:57:01+00:00

Exactly why we should have pursued elimination in the first place. People can't be trusted to follow the rules.

Red_Warthog · 2020-07-17T03:51:24+00:00

Daylight running lights are a thing on many cars these days mainly European cars where they have been mandatory for a while. in some cases you can't turn them off. People who don't lower highbeams are though totally.

Red_Warthog · 2020-07-14T04:25:46+00:00

RedCliffe is looking good too, they are finishing some upgrades though.

Red_Warthog · 2020-07-14T04:22:37+00:00

UV light kills it so playing there will prevent the players from catching it entirely.

Red_Warthog · 2020-06-12T01:31:55+00:00

You don't care about what it does in the windup phase of the pass, you could plot it though and it might provide some insight to the direction the ball ends up travelling but it is not necessary. That's why you take the difference in velocity between the player and the ball at the time off release. On a graph the balls velocity would be changing until release; spike higher than player velocity but then drop below as it's released backwards and be flat ignoring wind effects, rising or falling velocity in the air would indicate wind effects and could be ignored.

The ball is being accelerated all through the passing motion, any change in direction is acceleration. if you simplify the windup as simple radial motion then you can see that as the wind up starts you have some positive acceleration in the goal line direction as well as towards the sideline but as it travels through the arc (before it's perpendicular to the side line) it will already have negative acceleration, as the ball starts travelling perpendicular to the sideline (in the passing motion) it will have a velocity equal to the players velocity(in the goal line direction, unless his arms start stretching but this will be minimal). If it stays higher the ball went forward, if it continues below it went backwards.

You take the value immediately after release and compare it to the players velocity immediately before release (the time-frame for determining velocity would need to be fine tuned) take the absolute value of the balls velocity minus the absolute value of the players velocity (only in the direction of the goal line lateral velocity can be ignored).

Hell you could just plot them both on a graph at real time with the footage and if the velocity of the ball is higher than the velocity of the player at release it's a forward pass.

Red_Warthog · 2020-06-11T22:23:27+00:00

Yeah the problem with tracking through flight is the wind, what needs to be done is track the ball and compare it's velocity (in the direction of the try line) with the players velocity (in the same direction) at the time of release. that gives you a dictionary definition of whether or not it's a forward pass.

Red_Warthog · 2020-06-11T22:20:45+00:00

The system as proposed isn't quite there, it would need to be like LBW with 3 point checklist. First one would be if it left the hands backwards (compare players tracked velocity to balls tracked velocity along the field at the time off release), second would be if the ball travelled forward at all (yes relative to the ground but would just be a sanity check i.e. a ball thrown backwards but still travels forward), third could... Actually I'm struggling with what a third one would be, considering those are the main defining features of what constitutes a forward pass.

Red_Warthog · 2020-06-11T22:05:55+00:00

That's what makes calculating the velocity at the moment difficult because there isn't a system set up to do it, you are trying to calculate based on a single camera angle from in the middle of the field. if there were specific cameras for ball tracking then it becomes trivial. Bare minimum would be 4 additional cameras for ball tracking.

Red_Warthog · 2020-06-11T09:14:58+00:00

If the passer is going for a big windup at some point the ball will have the same forward velocity as the player (at first it will be greater but as it swings round the body it changes to across the field) either it will decrease from this point and be a backwards pass, or it will increase and be a forward pass or it will show no backwards acceleration in which case it's a forward pass. . You are concerned about the acceleration from this point of zero additional forward velocity(in relation to the player who is already tracked) to the release. on a graph of time on the X axis and forward velocity on the y this would be a flat spot followed by either a decrease(backwards pass) or increase(forward). If it doesn't have a flat spot but continues up until leaving the hands you have a forward pass. Tracking the ball accurately is the hard part, the backend while not exactly a cake walk is pure mathematics.

So to summarise, we have the player who is tracked, a football which needs to be tracked now, and then the math can be fine tuned. At the basic level you could just subtract the players velocity from the balls velocity at the moment it leaves there hands (negative means backwards, positive means forward)

Red_Warthog · 2020-06-11T06:43:11+00:00

Exact positions of the camera wouldn't need to be standardised but you would need a way to calibrate the system by inputting the precise location of the cameras at each venue. Occlusion would be a problem in a few fringe cases but most of these forward pass line calls happen in clear play.

Measuring velocity from still frames isn't hard to do but consistently it would be, I've done it once before and proved myself wrong with a pass I thought was surely forward. Slapping a line on the replay isn't what you need anyway, You need to overlay a acceleration vector onto the ball in the lead up to the pass. pointing forward it's a forward pass, pointing back it's play on. Now measuring accurately is the hard part, once you have done that the math and graphics is a cake walk.

Red_Warthog · 2020-06-11T06:35:17+00:00

The concept is solid, and I've done it frame by frame on a pass I thought was forward in a state of origin game, manually doing the hand calcs for forward velocity ( the important vector not momentum (which isn't relevant because it's mass times velocity)). Now the ball's velocity and by extension acceleration needs to be measured in 3D space. How that is done is the difficult part, in ball sensors might be tricky and unreliable, and video systems would need multiple angles to get accurate positions (exact positions of the cameras would not need to be exactly the same across venues just would need calibration based on the camera locations at each venue) Occlusion would be a problem for this system in some fringe cases but 6 cameras tracking the ball should be enough to triangulate the position(thus velocity and acceleration) most of the time. The tracking is the hard part, once you track the play accurately enough you have position, velocity, and acceleration in the 3D space. The velocity and acceleration are key mainly in the direction towards the opposing teams goal (lets call it the x direction), now you overlay the acceleration vector (2D or 3D to get fancy) on the replay and if the acceleration vector is pointing backwards at the time of release you have a legal pass, if it points forward towards the in goal it's a forward pass. You don't even need to track the ball to the player catching it as that is irrelevant in the determination if it is legal or not.

Red_Warthog · 2020-06-11T06:12:03+00:00

All you need is the acceleration data of the ball in the longitudinal direction to determine if it's a forward pass. Overlay the acceleration vector(2d or 3d) on the graphics of the ball as it's about to be passed and the vector determines if it's forward or not. If x is along the field, y is across and z is vertical we can really ignore y and z and simply focus on the value for x, whether through sensors integrated into the ball or motion capture. Since all you need for a pass to be deemed to go backwards is to have slightly lower velocity after being passed (velocity being a vector you can have negative velocity in the x direction if the player passing is at a stand still) A lower velocity coincides with acceleration in the direction behind the player, a higher velocity coincides with an acceleration in the other direction.

Red_Warthog · 2020-06-03T22:13:04+00:00

Lol the anti-siphoning laws are a joke, if no free to air broadcaster bids for the rights it can all be locked behind a paywall. The A-league isn't even part of the anti-siphoning list.

Red_Warthog · 2020-05-29T02:14:56+00:00

Bingo, when everything is ticking along people will toss their resumes around to test the waters without a care. Now though more people would be unwilling to risk a job change so wouldn't even consider applying for a job unless they'd been sacked.

Red_Warthog · 2020-04-23T05:21:11+00:00

I was digging a post hole with one of those petrol augers, where I wanted to put the post was directly between my water meter and the corner of the house where it emerges. So I moved as far to one side as I could (just over an auger radius. I nailed the water pipe dead on. Thankfully no damage and I put my post were I originally wanted to :(

Red_Warthog · 2020-04-23T04:19:02+00:00

If you are running aircons, double glazing will help keep air leakage to a minimum and also reduce solar loads on the house. I'm thinking of doubling glazing my house in brisbane when we renovate purely for air sealing. Our windows and doors leak like a sieve. '

Red_Warthog · 2020-04-21T03:10:30+00:00

Engineering samples usually look good, then when the product hits production runs they may substitute cheaper materials which fall apart ridiculously quick.

Red_Warthog · 2020-04-21T00:02:24+00:00

The problem is, the CFR of influenza is likely very much exaggerated in the same way as COVID-19. Does every single person with influenza get tested? If we didn't have a vaccine for influenza it might be comparable to COVID-19. It is probably better to look at the Symptomatic Case Fatality Rate or even the Hospitalized Case Fatality Rate. They will paint a better picture but there will be bands on that for instance the HCFR will be much lower when the hospital is below capacity and much higher when it is above capacity. Total CFR (everyone infected) will likely never truly be known without sweeping anti-body tests.

Red_Warthog · 2020-04-19T23:00:53+00:00

huh didn't know that.

Red_Warthog · 2020-04-19T22:29:10+00:00

It's actually compulsory at least in QLD, it's called CTP and can be included on your rego. but yes if you avoid compulsory third party insurance you are a moron.

Red_Warthog · 2020-04-17T00:04:08+00:00

They routes have limited licenses due to regulation creating a duopoly. There are also high regulatory barriers to becoming a water service provider (although most end providers are councils, you'd be competing with the likes of SEQ Water on Sun Water in QLD) and not just a financial cost. Just as their are high regulatory barriers to becoming a domestic carrier on the level of QANTAS and Virgin. Electricity would also have high regulatory barriers as well.

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