MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
01 Apr 2018, 17:52#1
We saw a Saders try denied by a forward pass today...but Joel and his commentary box trolls seemed to think it was okay.....his hands were going backwards. How in the blue blazes can you ever judge that, but of course it's often used to excuse a blatantly forward pass.
But not always JdV's pass with hands seemingly going backwards was denied in the WC 2011 semi. It's ruled differently every time, because it's all a question of perception and let's be honest, bias.
The truth is 95% or more of passes are clearly backwards as the rule was initially intended. Why do we bend the rules for the other 5%?
The drift theory is a rather dubious extension of the relative motion rule. If the ball truly comes out the hands going backwards....it's going to go backwards. There is no other physical force that interferes with the ball once it is in flight.
The fact is it's not coming out going backwards....the angle of the hands is not sufficient to offset the forward motion of the player. There is no 'drift' it all happens the instant the ball leaves the hands after a new force vector has been applied. So if the hands are aimed backwards it's no guarantee, and shouldn't be the criterion.
Rugby requires a lateral or backward pass.....so if you are at pace you need to aim it well behind where you are. And if you are throwing a long pass, the receiver needs to be at least two steps behind the passer to catch the ball at pace. If he isn't and doesn't have to break stride, the pass has gone forward.
Part of the problem is the angle presented by the receiver, at longer distances....given a relatively flat backline that angle diminishes dramatically for receivers further away....making the angle of the pass flatter and a resulting forward pass due to motion more likely.
It's time to go back to the only rule that can be fairly applied....the pass has to be lateral or backwards. The good news is it only affects a very small number of passes.
JWJust_win
Captain18,570 posts
JWJust_winCaptain18,570 posts
01 Apr 2018, 20:00#3
Great April fools joke Beeno. Let's see how many people believe you
02 Apr 2018, 00:13#4
Mozart, did JDV not play for the Boks in 2011 as I don’t recall they made it to the semis....
KMKa Mate
Club Pro246 posts
02 Apr 2018, 00:41#6
This is the supposedly educated guy who doesn't grasp the fact that if player A and player B are both running at 20kph then if player A passes to player B the ball is also travelling forward at 20kph.
Now I'll be asked about force vectors and the like and I'll probably get asked to integrate the cubed root of pi, but what is obvious is the bloke who doesn't understand the basic concept of the ball coming out flat from the hands, something any kid playing rugby in NZ knows.
Nothing wrong with the forward pass rules. Not if you understand the fundamentals of physics and some of the basics of rugby.
MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
02 Apr 2018, 01:17#7
So tell me what force is acting on the ball, once it leaves the hand of the passer. It doesn't 'drift' it flies in a straight line along the path it assumes as it leaves the hand.....that path is determined by the forward motion of the passer and the angle of the hand.....the law of relative motion.
So just to show how ludicrous the law is.....with the same angle of the hands , one ball may actually go forward, and one backwards depending on the speed of the runner.
Perhaps the ref should add a speed factor to his instant computation of the angle of the hands.
It's a highly variable judgement with different refs seeing different things.
MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
02 Apr 2018, 02:05#8
Perhaps this will help you understand the dilemna. No ref can make this kind of call:
'The most important point to realize is that the ball will maintain its momentum from when it was being carried by the player (by Newton's First Law of Motion, also known as the Law of Inertia).
In order to calculate the overall, combined effect of these two forces on how the balls travel, we have to add the vectors, creating the new vector a + b. To do this, we simply move in the direction and magnitude of b, then in the direction and magnitude of a, as below.
As we can see here, despite the player passing the ball backwards, the ball has actually travelled forward! So is this technically an illegal forward pass?
The official rules state that a forward pass occurs when a player "throws or passes the ball towards their opponents' dead ball line." However, in the above examples, the player has thrown the ball backwards, but the ball itself has travelled forwards relative to the ground. In other words, the ball must be travelling backwards relative to the passer when the ball is released. The IRB has agreed to this definition.
Most rugby players or officials don't think about this, as if the players carry on their run, then it creates the illusion that the ball is travelling backwards anyway, but there are a couple of situations where the officials have clearly not thought about or remembered the effect of momentum, and some incorrect calls are made.
One example is when the players are unfortunate enough to be passing when next to one of the pitch's horizontal lines. The umpire can see much more clearly that the ball has travelled forward relative to the ground, and thus the illusion that the ball has travelled backwards, which the umpire usually relies upon, is destroyed. Thus many incorrect calls are given.
The other common error is when the passer is impeded shortly after making a pass.
In this case, when the passer is tackled shortly after making the pass, the ball ends up overtaking the passer, meaning that it is suddenly very noticeable that the ball has travelled forward, and the umpire stops play. However, the fact that the passer was stopped does not mean that he passed the ball forward, it was only momentum that carried it towards the opponents' end. This is why so many forward passes are given when offloading from a tackle.
Umpires need to be made more aware of these phenomena so they can enforce the laws with more consistency. Bryce Lawrence, in particular, fell foul of this in South Africa's 2011 World Cup game against Australia, with exactly this situation occurring at 3:48 in the following video. South Africa lost this game by only 2 points and went out of the World Cup, so this decision changed everything.
As well as in Rugby, relative velocity is very important in other areas of Physics. For example, I stated earlier that all velocities and speeds are relative. However, this was not quite true, there is one exception, and that is at the speed of light.
Einstein's Theory of Special Relativity shows, and relies on the fact that the speed of light is the same for any observer, regardless of their own velocity, when in a vacuum. This means that if you are travelling at a speed very close to the speed of light, and your friend next to you is stationary, then light will have exactly the same velocity relative to either of you. This seems nonsensical, but it has been proven conclusively in experiments, and has the remarkable result that the faster you are travelling, the slower time passes. In other words, Einstein proved that time itself is always relative. You can read more about this in our previous post on Special Relativity and its effect on time.
In conclusion, we've shown how relative velocity affects everything from Rugby to Einstein, and how a lack of knowledge of Physics can lead to some major mistakes from line judges, and confusion for spectators and players. Hopefully the Rugby authorities will continue to work hard to educate officials on these topics and maintain consistency.'
That from the Physics of Rugby: Forward Passes and Relativity.
MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
02 Apr 2018, 02:09#9
The only thing that's wrong with that analysis is this:
'The ball must be travelling backwards relative to the passer when the ball is released. The IRB has agreed to this definition.'
....which of course assumes both ball and passer are travelling forward. The only requirement is the ball is not travelling forward relatively as fast as the passer.
But of course if the quarter back in gridiron is running forward and throws a lateral but forward pass he could esily maintain a speed that would keep him ahead of that forward pass.....ie the ball would be travelling backwards relative to the passer.
It's obviously a different calculus ....mostly that the hands are turned backwards. Almost impossible for a ref to judge,
MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
02 Apr 2018, 03:15#11
Nice, can you do it with a sheep?
MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
02 Apr 2018, 03:50#13
Hahaha touchy....but let me leave it there.....the ball comes backwards out of the hands and then zooms forward. What exactly the force is that causes it to veer off the path it started on remains a bit of a mystery. But given the effect of forward momentum is dialed into it's first infinitessmal movement out of the hand, this has to be another mystery Ka Mate force.
LMAOFY!
MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
02 Apr 2018, 16:05#20
Interesting post, but I disagree....most passes are short and the receiver is almost always a couple of feet behind the passer. This encourages a back pass......it's an angle thing.
As for the receiver ahead of the passer notion.....you could throw a NFL pass and still be legal under that variation.
The fact is a judgement has to be made....right now the ref has to make a judgement on angle of hands, speed of the runner, spin as you rightly point out....which almost always works the ball backwards.
How much simpler to make a judgement about whether the ball itself has literally TRAVELLED FORWARD.
And if we don't, we have travesties like the JdV very marginal forward pass in the WC deciding a crucial match...with the knowledge that a different ref would have called it differently
MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
02 Apr 2018, 22:17#22
Take that superb long pass Mckenzie manufactured at minute 14 of the Landers game. He was one metre inside the 10 metre line when it was thrown and it was received by Messum on the 10 metre line......'drift' or no 'drift' it went. 1 metre backwards.
McKenzie wasn't running flat out some might say....but very few long passes are launched by players at the full run. In the meantime Messum took about 9 strides....ie he was well behind the passer in order to make a legal reception.
That's how rugby is supposed to work, just like lineout throws and scrum feeds are supposed to be straight.....the tinkering with these old rules is just making rugby officiating a crap shoot.
MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
03 Apr 2018, 16:43#29
Yes exactly......the effect of motion is on the direction of the ball as it leaves the hands.....not when it is in the air.
'Drift' is an embarrassing bit of ignorance..do shells fired from a moving destroyer curve? Yes, in a vertical plane....they go dead straight horizontally.
MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
03 Apr 2018, 20:16#33
It can only be justified and properly measured based on a fact.....ie did it travel forwards. Hands going backwards is a judgement the officials have to make....and is highly subjective.
A forward pass is a forward pass....this is just creeping rule breaking as are so many things in modern life.
MOMozart
Captain49,914 posts
MOMozartCaptain49,914 posts
04 Apr 2018, 00:43#35
Well that is a perfect illustration of what I have said. The video says it doesn't come forward out of his hands.....but it does.....the micro second the ball emerges from his hands it's going forwards.
It goes forward because both the angle of the hands and movement of the passer are simultaneously affecting the ball...right up to the instant it leaves the hands.
Nor is there any drift.....the ball flies dead straight.
The question is whether the motion is what we want to police.....or the result.
If you go with this bogus hands back in the pass rule:
1 Backlines become flatter with less space to beat the tackler,
2 Forward pass calls are purely subjective, no ref can judge the motion of the hands in the zone of uncertainty.
3 Long passes and passes close to cross markings are more likely to be called....because at the end of the day a pass made outside the 22 caught inside the 22 is always going to look suspicious.
In the old days a pass had to be caught flat or behind the point it was passed...that's clear cut and fair. And it's also true of most rugby passes.
But all of the passes opening that video were unfairly forward.
04 Apr 2018, 07:55#36
Moz I am with you here. CC also made a very straight forward point. A ball is passed from a specific point on the field. If the ball is received in line with or behind that point, it is fine. Anything else is a forward pass. When you bring things like momentum, direction of hands and other arbitrary variables into the equation, you are going to have endless issues based on various interpretations....which is exactly what we have now. It just leaves a space for crooked officials to thrive.
LIlimpfischer
Newbie5 posts
04 Apr 2018, 11:12#38
To Mozart and all who agree with his viewpoint, let's look at just the Sharks Blues game from the weekend.
youtube.com/watch?v=edhl0SG7yuE&t=15s
Let's see how many tries would be disallowed under Mozart's rule
Forward pass at 0:57, (1)Forward pass at 1:32, (2)Marginally forward pass at 1:50, take note of the Barfoot sign as reference, (3)Forward pass at 2:25, (4)Forward pass at 3:00, (5)Forward pass at 3:41, (6) (this looks like a good pass but drifts about a metre forward as you can tell by the white line lying perpendicular to the 10m line)
The best example though is at 3:18 where the player releases the ball clearly short of the halfway line yet is caught by the receiving player on the halfway line.
Do you honestly believe that this should be called a forward pass??
That makes 7 of the 12 tries scored that night illegal if we were to enforce that rule. And that's just the tries.Are you guys really that fed up and angry with south african rugby that you suggest such a radical overhaul to the sport?
