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Author Topic: Track marks and our use of 10ft  (Read 16570 times)

Offline llama of death

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Track marks and our use of 10ft
« on: August 16, 2016, 05:28:49 pm »
Ok so you may know by now I am  derby geek. In my geekery I noticed the 10ft marks don't feel like 10ft in the corner, so I measured.

I found out that on that track they where very well centered in the lane and the markings for 7ft .5 inch where still visible (and measure true) yet the ticks where not at 10ft. Instead they grew from just over 10ft to over 11ft in spacing.

I decided to investigate and CAD drafted a few layouts to test my theories.

Theory 1: The WFTDA standard method doesn't create 10ft marks even in a best case scenario.

Theory 2: The WFTDA method of marking contradicts the rules, specifically the part where all distance between persons should be measured parallel the inside line (their use of parallel is a topic for another time).

Theory 3: There is a way to minimally tweak the design to produce a truly 10ft spread which stays parallel the inside line.


Tests: ***ALL MEASUREMENTS ARE IN DECIMAL FEET UNLESS OTHERWISE STATED IN THE DRAWINGS****
Attached are four versions of the track. Each uses a different method to lay the tick marks.

First is the WFTDA standard to the published layout guide.


Second: The true center method **Note: for this to work the center of the track must be measured at the midpoint between the true center and offset center marks**


Third: The Easy method (not true center and looks odd to skate it when you are use to marks in the center)


Fourth: A final version where I take the best practices found above and make a system which is simple and gets repeatable accurate results.




Analysis and conclusions:

**The original WFTDA layout was procedurally generated with the same methods track is laid. Measurements where added to show the errors inherent in this method.**

Unless I am mistaken the use of radial lines spread at 7ft .5 in is not ideal for setting true 10ft marks as it at no point creates a true 10ft spacing. This is made worse by the use of a center of track placement of the ticks. By doing so they are guaranteed to grow in distance apart and never be parallel the inside line.

Several methods are available to fix this. I believe with WFTDAs intent to have the marks as near the center as possible the best course is to choose a method which is not true "center of track" but approximates it. Further more only a small adjustment to the 7ft .5 in measurement would create a truly accurate marking system.


My final recommendation for change in procedure is thus:
Keep the track layout the same save for the following changes. First, use 6ft 5.5inch  in place of 7ft .5in. Second use a radius of 19.5 centered on the true center of the track to make the marks appear centered and cordial to the center of the track.

____________________________________________________


Thoughts?
I play devils advocate a lot, it is always because I desire a complete understanding of the rule/scenario. I do make changes to my reffing often as a direct result of discussions resulting in a consensus. Particularly if it is contrary to my previous understanding.

Offline llama of death

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Re: Track marks and our use of 10ft
« Reply #1 on: August 16, 2016, 05:32:25 pm »
The idea being that if the intent of the marks is a guide for skaters they should represent true 10ft distances as described by the rules (parallel the inside line and always 10ft). If the intent was to use them as learing aids for referees and skaters they should again be adjusted to fit the rules as above.

If the intent was to make wildly approximate markings which have no real bearing on distance and do not necessarily fit the rules we are to enforce than we can stick with the markings and we should avoid using the lines even as reference as referees.
I play devils advocate a lot, it is always because I desire a complete understanding of the rule/scenario. I do make changes to my reffing often as a direct result of discussions resulting in a consensus. Particularly if it is contrary to my previous understanding.

Offline Major Wood

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Re: Track marks and our use of 10ft
« Reply #2 on: August 16, 2016, 06:05:56 pm »
The idea being that if the intent of the marks is a guide for skaters they should represent true 10ft distances as described by the rules (parallel the inside line and always 10ft). If the intent was to use them as learing aids for referees and skaters they should again be adjusted to fit the rules as above.

If the intent was to make wildly approximate markings which have no real bearing on distance and do not necessarily fit the rules we are to enforce than we can stick with the markings and we should avoid using the lines even as reference as referees.

The original layout document included full width lines (which I greatly prefer and still use locally). It was acknowledged by pretty much everyone that the lines were very far from perfect for measurement in the turns. That was what lead to hash marks becoming common. I don't know anything about what went into the original track design, so I can't speak to intent, or how they landed on 7' 1/2" (I've long advocated for using decimal inches, which would prevent a very common mistake, since it would be 84.5" instead of being accidentally read as 90"). I believe that they were only intended as a guideline, acknowledging that they could not be perfect.

If we're being honest, any more than dots are going to be inaccurate. This is part of the reason that I advocate for full width lines. The other is that they are very useful for determining direction.
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Offline llama of death

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Re: Track marks and our use of 10ft
« Reply #3 on: August 18, 2016, 03:30:57 pm »
The original layout document included full width lines (which I greatly prefer and still use locally). It was acknowledged by pretty much everyone that the lines were very far from perfect for measurement in the turns. That was what lead to hash marks becoming common. I don't know anything about what went into the original track design, so I can't speak to intent, or how they landed on 7' 1/2" (I've long advocated for using decimal inches, which would prevent a very common mistake, since it would be 84.5" instead of being accidentally read as 90"). I believe that they were only intended as a guideline, acknowledging that they could not be perfect.
So the question is why did no one attempt to lay track at a set distance with more accurate distance (something like the 19' 6", 6' 5.5" measurements I propose). It is clearly closer to accurate and still very simple to lay.

And yes the wording they use of feet and inches is easier to mistake when written as 7' 1/2". I would imagine the reason for this wording being most measuring tapes do not measure in inches only but instead feet and inches.



If we're being honest, any more than dots are going to be inaccurate. This is part of the reason that I advocate for full width lines. The other is that they are very useful for determining direction.
While this is true that dots are the only truly accurate marking device, I know of zero refs at all who are more accurate than the width of a 2" tape at gauging distance. So while a 1/2 tape fill width with a dot at 19.5 feet on spacing of 6' 5.5" would be the most accurate markings we lay, I am hoping just to get people thinking about the options here and why WFTDA would go with such an obviously broken layout, with neither marks which are parallel the inside line nor even actually 10ft at any point in the first place.

If we are to use marks which are wholly inaccurate I don't see a reason to have them at all as it just adds to the confusion of the game to tell skaters that these marks are 10' marks when they defiantly are not.


Anyway, the point wasn't for me to go off on a rant but to gather input and gauge if I am the only one out here who believes that there is a better way to mark the track. ( I really do like the idea of a .5" line with a 2" dot on it for 10ft marks, but it make look less... cool?... professional?)
I play devils advocate a lot, it is always because I desire a complete understanding of the rule/scenario. I do make changes to my reffing often as a direct result of discussions resulting in a consensus. Particularly if it is contrary to my previous understanding.

Offline Stray Taco

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Re: Track marks and our use of 10ft
« Reply #4 on: August 18, 2016, 03:40:45 pm »
Have you considered sending this idea to Timeout? If it improves on what's currently used it can't hurt to suggest it...
Mike "Stray Taco" Straw

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Offline General Hellativity

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Re: Track marks and our use of 10ft
« Reply #5 on: August 18, 2016, 05:01:42 pm »
It seems to me that the primary problem is that the centerline length of the track is not divisible by 10', so there is no mathematically correct solution to the problem. If I'm reading it right, it looks like your solution takes all the error and puts it into a "remainder" segment whose length is about 6'. That just *looks* bad. ;)

Offline llama of death

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Re: Track marks and our use of 10ft
« Reply #6 on: August 18, 2016, 09:13:22 pm »
Have you considered sending this idea to Timeout? If it improves on what's currently used it can't hurt to suggest it...

I have but as I rarely get a response much less a change from it I thought it more fun to discuss the concept.

BTW I laid this on a local track as a test and loved it, WAY less questioning of distance from coaches and players, and the fresshie refs where calling OoP much more constantly to the real 20ft distance instead of at the usual 22ish ft I've seen it called at.



It seems to me that the primary problem is that the centerline length of the track is not divisible by 10', so there is no mathematically correct solution to the problem. If I'm reading it right, it looks like your solution takes all the error and puts it into a "remainder" segment whose length is about 6'. That just *looks* bad. ;)

Yes it does, I/we noticed it looks way better as 15' 7" at the end (leave off the last tick mark).
I play devils advocate a lot, it is always because I desire a complete understanding of the rule/scenario. I do make changes to my reffing often as a direct result of discussions resulting in a consensus. Particularly if it is contrary to my previous understanding.

Offline ttjustice

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Re: Track marks and our use of 10ft
« Reply #7 on: August 22, 2016, 06:48:02 pm »
I have  used "true" 10' marks for years at OHRD- someone figured out the measurements years ago (I think it was Half Nelson) and I adopted it for our home games.  I use a 2' long piece of tape for each mark.  Everyone seems to like that very much.  I am not saying its better or worse than the WFTDA way, as Major Wood points out the long lines can be very helpful with determining direction, just that the true 10' has become our preference.

The reason you don't get responses much from Timeout is that it is monitored by one person (me) who then routes things to appropriate committees.  Many of the things submitted can't be answered due to confidential discussions, or if they are suggestions, we are now on a 2 years cycle so there can be a long delay before a committee actually gets to discussing things.  Its not that Timeout is being ignored its just the way the process works (at the moment).
Timothy T. Justice
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Retired Level 3 Skating Official
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Offline FNZebra

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Re: Track marks and our use of 10ft
« Reply #8 on: August 22, 2016, 07:45:00 pm »
@tt, I believe those short marks are accurate when they are placed 5'4" in from the inner track edge. The details are captured in these parts in an older thread addressing this very issue.
You will bout as you practice.


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Offline llama of death

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Re: Track marks and our use of 10ft
« Reply #9 on: August 22, 2016, 08:48:06 pm »
I have  used "true" 10' marks for years at OHRD- someone figured out the measurements years ago (I think it was Half Nelson) and I adopted it for our home games.  I use a 2' long piece of tape for each mark.  Everyone seems to like that very much.  I am not saying its better or worse than the WFTDA way, as Major Wood points out the long lines can be very helpful with determining direction, just that the true 10' has become our preference.

The reason you don't get responses much from Timeout is that it is monitored by one person (me) who then routes things to appropriate committees.  Many of the things submitted can't be answered due to confidential discussions, or if they are suggestions, we are now on a 2 years cycle so there can be a long delay before a committee actually gets to discussing things.  Its not that Timeout is being ignored its just the way the process works (at the moment).

That is presumably a very big job for one person.

@all

So am I to take it that the layout is a guideline not a rule or even a policy? To my understanding though the playoffs are required to use the layout as given?

Per: this link
I play devils advocate a lot, it is always because I desire a complete understanding of the rule/scenario. I do make changes to my reffing often as a direct result of discussions resulting in a consensus. Particularly if it is contrary to my previous understanding.

Offline Bluebeard

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Re: Track marks and our use of 10ft
« Reply #10 on: August 24, 2016, 09:56:18 pm »
Quote from: General Hellativitylinkd=topic=5073.msg51592#msg51592 date=1471536102
It seems to me that the primary problem is that the centerline length of the track is not divisible by 10', so there is no mathematically correct solution to the problem. If I'm reading it right, it looks like your solution takes all the error and puts it into a "remainder" segment whose length is about 6'. That just *looks* bad. ;)

@FNZ  by my calculations that looks like about 4 - 1/4 feet (4.211269)from the inside line.

@Llama what does that make the cad look like?

Offline Vanilla VICE

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Re: Track marks and our use of 10ft
« Reply #11 on: August 25, 2016, 05:11:33 pm »
These drawings are a little overwhelming, can someone tell me what the center track distance actually is? Sorry if it is very apparent in these drawings.
Muscogee Roller Girls: Columbus, GA
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Offline SeerSin

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Re: Track marks and our use of 10ft
« Reply #12 on: August 26, 2016, 12:57:17 pm »
My take on it is that it's not really broken. It works because everyone is using the same visual indicator. So even if we're calling "no pack" at 10.5' one place and 11.2' in other places it's a predictable call. The skaters know that call is coming and can still base their strategies on it. But them I'm one of those "reffing is more art than science" people :)

That being said you have a very compelling idea here that's definitely worth looking into. I'm especially excited about your indication that newer refs may be finding it easier to call no pack and OOP correctly. I think you should send it in to timeout. However I wouldn't expect anything to happen quickly. We've been using the same track layout for a long time and WFTDA membership is going to think long and hard(and probably test) before making such fundamental changes.

Offline llama of death

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Re: Track marks and our use of 10ft
« Reply #13 on: August 26, 2016, 08:34:42 pm »
These drawings are a little overwhelming, can someone tell me what the center track distance actually is? Sorry if it is very apparent in these drawings.
True center of track is an odd beast. I'll break it down like this:
The inside and out side lines do not share a center point, they are offset by 1 counter clockwise.
To find true center one would need to use a third 6" mark (halfway along the 1ft offset).
The distance to this mark would be just under 19.5ft (19.4996ft to be precise).

However the center of the track is really a moot point, as because it does not share the same center point with the inside line it is not parallel to it as infered by the rules. However we can achieve the appearance of a center line without losing parallel because the track is so large and people are not precise in their visual estimations.

To set a "center of track" which is parallel the inside line we simply move our 19ft 6in "center" to be the same center as the inside line.

Quote from: General Hellativitylinkd=topic=5073.msg51592#msg51592 date=1471536102
It seems to me that the primary problem is that the centerline length of the track is not divisible by 10', so there is no mathematically correct solution to the problem. If I'm reading it right, it looks like your solution takes all the error and puts it into a "remainder" segment whose length is about 6'. That just *looks* bad. ;)

@FNZ  by my calculations that looks like about 4 - 1/4 feet (4.211269)from the inside line.

@Llama what does that make the cad look like?

There is a way to forgo the center line entirely and achieve a even split of 10ft marks by setting the "center of the track" to be 20ft 10.75.


Personally I think non-center layouts look odd. Though this is better than it looks if you reduce the number of ticks by 1 and substantially shrink the arc.
I play devils advocate a lot, it is always because I desire a complete understanding of the rule/scenario. I do make changes to my reffing often as a direct result of discussions resulting in a consensus. Particularly if it is contrary to my previous understanding.

Offline Vanilla VICE

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Re: Track marks and our use of 10ft
« Reply #14 on: August 26, 2016, 09:39:14 pm »
These drawings are a little overwhelming, can someone tell me what the center track distance actually is? Sorry if it is very apparent in these drawings.
True center of track is an odd beast. I'll break it down like this:
The inside and out side lines do not share a center point, they are offset by 1 counter clockwise.
To find true center one would need to use a third 6" mark (halfway along the 1ft offset).
The distance to this mark would be just under 19.5ft (19.4996ft to be precise).

However the center of the track is really a moot point, as because it does not share the same center point with the inside line it is not parallel to it as infered by the rules. However we can achieve the appearance of a center line without losing parallel because the track is so large and people are not precise in their visual estimations.

To set a "center of track" which is parallel the inside line we simply move our 19ft 6in "center" to be the same center as the inside line.

Quote from: General Hellativitylinkd=topic=5073.msg51592#msg51592 date=1471536102
It seems to me that the primary problem is that the centerline length of the track is not divisible by 10', so there is no mathematically correct solution to the problem. If I'm reading it right, it looks like your solution takes all the error and puts it into a "remainder" segment whose length is about 6'. That just *looks* bad. ;)

@FNZ  by my calculations that looks like about 4 - 1/4 feet (4.211269)from the inside line.

@Llama what does that make the cad look like?

There is a way to forgo the center line entirely and achieve a even split of 10ft marks by setting the "center of the track" to be 20ft 10.75.


Personally I think non-center layouts look odd. Though this is better than it looks if you reduce the number of ticks by 1 and substantially shrink the arc.

I love you dearly but your answer did not have the length. <3 What is the full length of the center line as measured from the inside line? How many feet long is it? The circumference.
« Last Edit: August 26, 2016, 10:35:06 pm by Vanilla VICE »
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