forward passes

[Browner]

On a referees forum, you should really try to stick with the LotG definitions of "attacking team" and "defending team". :biggrin:

Of course you're correct - hence my apology ......... or are you ? ............. to follow the style of the LoTG definitions

Correct person: The opponent of an Incorrect person, in whose half of the hemisphere the definition is being considered.

As you're not in my hemisphere, you can't be the correct person ! :biggrin:

 

[RobLev]

Of course they can, very few rugby players can manage 10m/s (22mph) in boots on muddy grass - Olympic sprinters may go faster in spikes on a Tartan track. If a rugby player gets anywhere close it means there is nothing between them an the try line and they are generally not thinking about passing.

According to the Guinness Book of Records the fasted recorded pass was by Joe Simpson at 22m/s (48 mph)

So Joe at full pelt would need to pass around 30 degrees backwards for the ball not to go forward relative to the grass.

I think I've posted a link to the video of that record being set, which was not in a match. The players setting the record were taking a run up to throw it into a catchnet; so that 48mph includes a significant contribution from Joe's forward momentum...

Passing laterally, with the arms travelling across the body, he's unlikely to get the ball travelling at, I'd guess, much above 30mph.

 

[SimonSmith]

If I ever play GTNW with Joshua, Netherlands is the first to go.

 

[Ian_Cook]

According to the Guinness Book of Records the fasted recorded pass was by Joe Simpson at 22m/s (48 mph)

So Joe at full pelt would need to pass around 30 degrees backwards for the ball not to go forward relative to the grass.

That would depend how far Joe was trying to pass it; the longer the pass, the greater the backward angle required to kill he forward momentum.

 

[FlipFlop]

That would depend how far Joe was trying to pass it; the longer the pass, the greater the backward angle required to kill he forward momentum.

That is BS Ian. The physics is simple - you need to impact sufficient "backwards" momentum to offset the forward momentum. If done on an angle, then only part of the momentum is backwards, the rest lateral. The distance the ball is thrown in irrelevant, only the speed and direction it leaves the hands.

 

[L'irlandais]

Korkey's Six Nations Special critical of the iRB accepting the momentum pass.
Doh! Who is this guy & how does he get a slot on the BBC relating to rugby?

 

[Browner]

Any mathematical wizards out there?

If a player is running forward at say 20 mph, and releases the ball exactly lateral , then how further forward will the ball have travelled if it is caught 5m, 10m 15m or 20m from where it left the passers hands?

Ive just watched Burrells pass v Sarries & this set me thinking of the optimum, from which decisions could be benchmarked.

 

[Dickie E]

I imagine the arithmetic would be easier in a vacuum

 

[Browner]

I imagine the arithmetic would be easier in a vacuum

Nice 1.

 

[The Fat]

Would also vary depending on how hard the pass was thrown

 

[4eyesbetter]

First, assume a spherical ball...

 

[Ian_Cook]

Any mathematical wizards out there?

If a player is running forward at say 20 mph, and releases the ball exactly lateral , then how further forward will the ball have travelled if it is caught 5m, 10m 15m or 20m from where it left the passers hands?

Ive just watched Burrells pass v Sarries & this set me thinking of the optimum, from which decisions could be benchmarked.

Insufficient data. The result will depend on how fast the pass is thrown, among other things;

The simple solution is a vector diagram. In simple terms (discounting gravity which causes the ball to fly in a parabolic arc, and air resistance which will lead to deceleration)

The forward vector is momentum/forward velocity - we'll call that V[SUB]m[/SUB]
The lateral vector is the speed the pass is thrown - we'll call that V[sub]l[/sub]
The result is the distance and the direction the ball travels - we'll call that D[sub]f[/sub]

If the player is running forward at the same speed he throws the lateral pass, then V[SUB]l[/SUB] = V[sub]m[/sub]. The ball travels forward at an angle of 45°, (the black arrow)

If the player is running forward at half the speed he throws the lateral pass, then V[SUB]l[/SUB] = 2 x V[sub]m[/sub]. The ball travels forward at an angle of 26°, (the red arrow)

If the player is running forward at a quarter of the speed he throws the lateral pass, then V[SUB]l[/SUB] = 4 x V[sub]m[/sub]. The ball travels forward at an angle of 14°, (the green arrow)

It is easy to work out that so long as the player is running forwards, no matter how fast the ball is thrown, in a lateral pass, it WILL always travel forwards. Any value of V[SUB]m[/SUB] greater than zero will result in a forward angle of greater than zero. Its why the momentum rule makes sense and the classic interpretation doesn't.

Changes in the direction of V[SUB]m[/SUB] will alter the result, as will air resistance,

 

[SimonSmith]

That explanation reads like a scene from The Dambusters.

 

[Pegleg]

Hi richie, although you joined this forum in 2010 you may not have been active enough to realise that discussion of the forward pass borders on more fundamentalist than the Ayatollah.

I've always ignored 'lateral' passes. By which I mean, I have not once complained when a referee determined a pass was not forwards when I thought it was as a player, and now as a referee myself I give a heck of a lot of leeway, especially when I am fully aware of my own parallax error.

Having only followed the 1-day entry level IRB course, which prioritises the concepts of "Fair Contest" and "Continuity of Play", you can colour me unimpressed with those who believe that we are playing League. Because it is not a fair contest if the ball travels two or more metres forward, in my opinion.

That's my opinion. My advice is to ignore the "elite" interpretation in your own games, but even more so to ignore those who are incapable of polite discussion, such as the cretinous poster who replied "kill me now". Don't kill him, ok? He is not a union chap anyway.

Nobody has a problem with "very lateral" passes on the half-way line. I personally do when they are only 5 metres out and I am standing/moving on/near the 5m line. I have a much bigger problem with the condoning of massive forward passes (relative to the field), but that's just me.

The IRB is the ultimate authority. The Australian Video is the "law" ignore it if you want. But please don't advocate that others follow your false line.

 

[OB..]

If a player is running forward at say 20 mph, and releases the ball exactly lateral , then how further forward will the ball have travelled if it is caught 5m, 10m 15m or 20m from where it left the passers hands?

It depends entirely on how much lateral speed is imparted to the ball. If you could pass at the speed of light, the ball would be virtually instantaneously past your markers with virtually no forward movement.

For any pass, the forward component of its speed remains that of the passer. The slower the imparted speed, the longer it will take to travel a given distance.

Distance travelled is not a useful measure. What matters is the angle of the pass relative to the passer, which is not distance or speed related. To work back from distance to angle, you have to estimate the speed. Estimating the angle directly is much easier.

 

[Rushforth]

The IRB is the ultimate authority. The Australian Video is the "law" ignore it if you want. But please don't advocate that others follow your false line.

I beg your pardon? I've long since agreed that Ian is correct with "Its why the momentum rule makes sense and the classic interpretation doesn't." - but as you will note even he calls it the "classic interpretation".

Compare and contrast http://laws.worldrugby.org/index.php?law=12 with http://www.therfl.co.uk/the-rfl/rules/official_laws/10_knockon_and_forward_pass. It would be trivial to copy paste some of this, if desired, and not that much harder to provide a wording slightly different for the following scenario (perhaps under 12.1f):

Imagine that you are running to keep up with play, with players 20-30 years younger than yourself. A drift pass is given just over the 5m line, but you can't see hands because there are bodies in the way. The ball is caught on the goal line, where the defender knows he has to stand. Therefore there cannot be a tackle (the goal-line being part of the in-goal; tackles must be in the field of play). What should you do?

We may have different opinions on what the answer should be, and I would like World Rugby to clarify in LAW, not in a couple of youtube videos.

 

[crossref]

We may have different opinions on what the answer should be, and I would like World Rugby to clarify in LAW, not in a couple of youtube videos.

I certainly agree with Rushforth on that.

and to me the RFL law seems perfect.

NOTES
Direction of Pass 1. The direction of a pass is relative to the player making it and not to the actual path relative to the ground. A player running towards his opponents’ goal line may throw the ball towards a colleague who is behind him but because of the thrower’s own momentum the ball travels forward relative to the ground. This is not a forward pass as the thrower has not passed the ball forward in relation to himself. This is particularly noticeable when a running player makes a high, lobbed pass.

I'd like to see a passage like that in the RU Laws, and I can't really understand why they don't write one.
I'd also like to see Law 10 include a link to that video ...

 

[Browner]

If a player is running forward at say 20 mph, and releases the ball exactly lateral at 30 mph , then how further forward will the ball have travelled if it is caught 5m, 10m 15m or 20m from where it left the passers hands? (Assumes no breeze, no gravity, no air resistance, no spin, or any other diverting factor not specified)

.

OK, I've amended the question....anyone care to answer for the following distances?

5m
10m
15m
20m

 

[crossref]

OK, I've amended the question....anyone care to answer for the following distances?

5m
10m
15m
20m

running at 20mph, passing at 30mph, the runner is going to cover 2/3 of the distance of the ball.

So it's
3.33m
6.66m
10m
13.33m

In real lfe though
- he won't be runing 20mph (which is 11s for 100m)
- he will be passing the ball backwards relative to himself
so the ball won't travel that much forward realtive to the ground.

 

[OB..]

OK, I've amended the question....anyone care to answer for the following distances?

5m
10m
15m
20m

As I explained above, it depends on the speed of the pass, not just the speed of the passer..