Zebra Huddle™

WFTDA => General Ref Discussion => Topic started by: llama of death on August 16, 2016, 05:28:49 pm

Title: Track marks and our use of 10ft
Post by: llama of death 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.
(http://i25.photobucket.com/albums/c81/Editor-Mantyla/e471d0bf-f393-42f5-9ea7-caa3c33e364b.png) (http://s25.photobucket.com/user/Editor-Mantyla/media/e471d0bf-f393-42f5-9ea7-caa3c33e364b.png.html)

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**
(http://i25.photobucket.com/albums/c81/Editor-Mantyla/6a4b5899-e766-4db2-a4f3-f613f629167f.png) (http://s25.photobucket.com/user/Editor-Mantyla/media/6a4b5899-e766-4db2-a4f3-f613f629167f.png.html)

Third: The Easy method (not true center and looks odd to skate it when you are use to marks in the center)
(http://i25.photobucket.com/albums/c81/Editor-Mantyla/c1c8f73a-0777-425c-844f-6c8eae4781c0.png) (http://s25.photobucket.com/user/Editor-Mantyla/media/c1c8f73a-0777-425c-844f-6c8eae4781c0.png.html)

Fourth: A final version where I take the best practices found above and make a system which is simple and gets repeatable accurate results.
(http://i25.photobucket.com/albums/c81/Editor-Mantyla/5aa86987-19a1-4c13-93a6-c486d19eae74.png) (http://s25.photobucket.com/user/Editor-Mantyla/media/5aa86987-19a1-4c13-93a6-c486d19eae74.png.html)



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?
Title: Re: Track marks and our use of 10ft
Post by: llama of death 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.
Title: Re: Track marks and our use of 10ft
Post by: Major Wood 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.
Title: Re: Track marks and our use of 10ft
Post by: llama of death 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?)
Title: Re: Track marks and our use of 10ft
Post by: Stray Taco 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...
Title: Re: Track marks and our use of 10ft
Post by: General Hellativity 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. ;)
Title: Re: Track marks and our use of 10ft
Post by: llama of death 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).
Title: Re: Track marks and our use of 10ft
Post by: ttjustice 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).
Title: Re: Track marks and our use of 10ft
Post by: FNZebra 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.
Title: Re: Track marks and our use of 10ft
Post by: llama of death 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 (http://"https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwjL_K2B5dXOAhUW0mMKHaGyB7AQFggtMAI&url=https%3A%2F%2Fwftda.com%2Fresources%2Fwftda-tournament-track-setup-requirements.pdf&usg=AFQjCNGKtyfy_guEwQ6dmki_6RP4Mdgltg&sig2=jTrRCdJKM_LWPQAVpQbKDQ")
Title: Re: Track marks and our use of 10ft
Post by: Bluebeard 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?
Title: Re: Track marks and our use of 10ft
Post by: Vanilla VICE 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.
Title: Re: Track marks and our use of 10ft
Post by: SeerSin 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.
Title: Re: Track marks and our use of 10ft
Post by: llama of death 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.
(http://i25.photobucket.com/albums/c81/Editor-Mantyla/Track%20Markings%20Analisiys%20-%20Even%2010ft%20split.png) (http://s25.photobucket.com/user/Editor-Mantyla/media/Track%20Markings%20Analisiys%20-%20Even%2010ft%20split.png.html)

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.
Title: Re: Track marks and our use of 10ft
Post by: Vanilla VICE 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.
(http://i25.photobucket.com/albums/c81/Editor-Mantyla/Track%20Markings%20Analisiys%20-%20Even%2010ft%20split.png) (http://s25.photobucket.com/user/Editor-Mantyla/media/Track%20Markings%20Analisiys%20-%20Even%2010ft%20split.png.html)

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.
Title: Re: Track marks and our use of 10ft
Post by: llama of death on August 26, 2016, 11:20:12 pm
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.
"As measured from the inside line?"
I can't make sense of that part of your question.

The circumference? What good does that number do? I suppose if you wanted to do a really really rough est of the number of times one could cut the Cir into 10ft sections... kk, the circumference of the true center of track is 66.3175 feet.
Title: Re: Track marks and our use of 10ft
Post by: Vanilla VICE on August 29, 2016, 05:22:57 pm
Maybe I'm not asking the correct things. In the old appendix A for the track diagram it told you the length of the outside and inside track boundary.  I wanted to know what the approximate length would be if u added a "middle track boundary" or "center track boundary"

Length of the inside boundary = some number around 128 feet
Length of the outside boundary = some number around 256 feet
Length of the "center track boundary" (if one existed) =  ? Its some number around 180 feet I would guess (18 sections of 10 feet), but I just wanted to know what it was.
Title: Re: Track marks and our use of 10ft
Post by: llama of death on August 29, 2016, 07:17:36 pm
Maybe I'm not asking the correct things. In the old appendix A for the track diagram it told you the length of the outside and inside track boundary.  I wanted to know what the approximate length would be if u added a "middle track boundary" or "center track boundary"

Length of the inside boundary = some number around 128 feet
Length of the outside boundary = some number around 256 feet
Length of the "center track boundary" (if one existed) =  ? Its some number around 180 feet I would guess (18 sections of 10 feet), but I just wanted to know what it was.

C=2*Pie*R
The corner is ~a half circle we can estimate to prove my number is accurate by deving the C by 2.

R=19.5 ft

C=122.52
C/2= 61.26

And as you pointed out before there is a overage into the straight to account for of ~5 ft so my numbers of ~66ft is accurate.

Btw, the inside is 39.2699 ft and the outside is 86.2775. I am not sure where you pulled 128 ft from but that may be referencing the total perimeter of the track, as in how much rope you need.
Title: Re: Track marks and our use of 10ft
Post by: Vanilla VICE on August 29, 2016, 07:33:38 pm
I'm looking for the length of the perimeter of the metaphorical center track line. I'm going to keep figuring out different ways to ask this until there is some number around 180 feet as your answer lol

GH mentioned this number wasn't divisible by 10, so I want to know what the number actually is.
Title: Re: Track marks and our use of 10ft
Post by: llama of death on August 29, 2016, 08:22:28 pm
I'm looking for the length of the perimeter of the metaphorical center track line. I'm going to keep figuring out different ways to ask this until there is some number around 180 feet as your answer lol

GH mentioned this number wasn't divisible by 10, so I want to know what the number actually is.

As in a full lap distance? As skated down the middle of the track? That would be 192.5ft.
Title: Re: Track marks and our use of 10ft
Post by: Vanilla VICE on August 29, 2016, 08:45:46 pm
I'm looking for the length of the perimeter of the metaphorical center track line. I'm going to keep figuring out different ways to ask this until there is some number around 180 feet as your answer lol

GH mentioned this number wasn't divisible by 10, so I want to know what the number actually is.

As in a full lap distance? As skated down the middle of the track? That would be 192.5ft.

Winner winner winner.
Title: Re: Track marks and our use of 10ft
Post by: llama of death on August 29, 2016, 11:59:28 pm
I'm looking for the length of the perimeter of the metaphorical center track line. I'm going to keep figuring out different ways to ask this until there is some number around 180 feet as your answer lol

GH mentioned this number wasn't divisible by 10, so I want to know what the number actually is.

As in a full lap distance? As skated down the middle of the track? That would be 192.5ft.

Winner winner winner.

Still not sure why that is more relevant (or easy to use to arrive at an accurate layout) than the measurement of the corner arc length alone; nor better than setting an array of 10ft circles with centers along an arc with common center point and no defined radius, then simply choose how many 10ft radius circles one wants to span the arc length.

Anyway, in the end there are a few ways to set 10ft marks listed here which achieve more or less the desired reflection of the rules and are easy to layout repeatably.

Let me know if any of you test them out and have thoughts on their viability. (My home league is allowing me to Alpha test them on our track to get some initial opinions about them)
Title: Re: Track marks and our use of 10ft
Post by: Vanilla VICE on August 31, 2016, 03:27:29 pm
Probably because you're trying to solve problems and I'm just barely at the point of understanding what the problem is.  8)  You're trying to find a reason why I would want to know, there isn't one. I was just curious what it was.
Title: Re: Track marks and our use of 10ft
Post by: The Sharmanator on September 03, 2016, 01:15:57 am
I think a DME Arc would work
Title: Re: Track marks and our use of 10ft
Post by: General Hellativity on September 03, 2016, 12:11:30 pm
I think a DME Arc would work


No, because technically it can't be intercepted anywhere but the IAF. ;)
Title: Re: Track marks and our use of 10ft
Post by: Stony Hawk on September 04, 2016, 03:21:49 am
Llama,

I have autocad but not sure how to post cad images here.  Try this configuration on your side.  It demonstrates how the 10' marks are exactly created with the current published method

Draw out the track boundaries in the usual way and use the standard 84.5" array to plot the track marks through the inside track boundary.  This gives the 5 segments in the curve and one polysegment as we exit the curve and enter the straight.

Next:  from the center point, draw an arc with a radius of 210.05" (17"-6.05").  The arc length will be 660" in the curve.  The 5' of the straight adds another 60".  This gives us a total arc/line length of 720".  As long as this total length is divided equally, we will end up with six segments that are 120" each (as measured by the arc length)

This what the 7' 1/2" measurement does.  The angle of the first five segments will be 32.719 degrees.  The last partial segment will be 16.403 degrees.

(At the R210.05 arc line). If you look at the arc length in each segment, it will be exactly 120" (10').  The last segment will consist of an arc length of 60" and a straight length of 60".  So the last poly segment is also exactly 120" (10')

I'll try to figure out how to post the cad image.

So, it's true that radius line I mentioned is not near the center of the track.  It's ~5' from the inside track boundary.  But, we at least have exactly 10' apart for each segment for at least one symmetrical distance from the inside track boundary.

Let me know if I can clarify in any way.
Title: Re: Track marks and our use of 10ft
Post by: Stony Hawk on September 04, 2016, 03:15:10 pm
Here is the cad drawing to go with the previous post

Title: Re: Track marks and our use of 10ft
Post by: llama of death on September 06, 2016, 05:20:34 am
Here is the cad drawing to go with the previous post

I will have chance to get to this in the next few days but there is a inconsistency from wftda outline to the drawing you provided. Note I have not reproduced your described method but the error is visable seen.

They says "...placed alongt the line of   the string in the middle of the track..."

There is a major difference between your drawing which uses a constant radius of 17ft 6. A constant radius sharing the same center point as the inside line cannot create marks which are center to the track. The track boudary lines do not share a center point so an arc through the center must have its center at the midpoint of the line between the two.

I will try and get around to retracing your description later but I can tell you it does not represent a standard wftda layout.
Title: Re: Track marks and our use of 10ft
Post by: Stony Hawk on September 06, 2016, 03:06:51 pm
Llama,

Until I read your post, I took the below language from the WFTDA Track Layout guide at face value and never checked it.

     “a 1-2 foot (or 0.30-0.60 meter) tape marker can be placed along the line of the string in the middle of the track, and these tape markers will measure 10 feet (or 3.05 meters) from each other along the track.”

As both our measurements demonstrate, this statement is absolutely not accurate.   

My drawing only uses the standard layout in that I am still using 7’ ½” distance to plot the radial marks on the inside track boundary.   In order to get the marks to be 10’ from each other, my calculations indicate that these marks should 5’ from the inside track boundary and not ‘in the middle’ of the track as the guide indicates.

So, one question that I have is why does the official layout guide make this false statement?   

Second question, does anyone have a problem with altering the official method to actually plot these marks 5’ from the inside track boundary as opposed to the middle of the track?

Also, how did you get your image to imbed in your post rather than appear as an attachment

Title: Re: Track marks and our use of 10ft
Post by: Stray Taco on September 06, 2016, 03:38:07 pm
Llama,

Until I read your post, I took the below language from the WFTDA Track Layout guide at face value and never checked it.

     “a 1-2 foot (or 0.30-0.60 meter) tape marker can be placed along the line of the string in the middle of the track, and these tape markers will measure 10 feet (or 3.05 meters) from each other along the track.”

As both our measurements demonstrate, this statement is absolutely not accurate.   

My drawing only uses the standard layout in that I am still using 7’ ½” distance to plot the radial marks on the inside track boundary.   In order to get the marks to be 10’ from each other, my calculations indicate that these marks should 5’ from the inside track boundary and not ‘in the middle’ of the track as the guide indicates.

So, one question that I have is why does the official layout guide make this false statement?   

Second question, does anyone have a problem with altering the official method to actually plot these marks 5’ from the inside track boundary as opposed to the middle of the track?

Also, how did you get your image to imbed in your post rather than appear as an attachment

I'm not knowledgeable of CAD, but from the posted picture, one thing I noticed was that it was 10-foot arcs, which is different from two lines that are ten feet apart.

My understanding of pack definition is that it's determined by straight-line distance, even around the apex (as in a straight line run from the tangent of the inside boundary where the Skaters are.

[rule]3.1.2.1 - Distances for determining the pack and the Engagement Zone are measured as the shortest distance parallel to the inside track boundary between Skaters’ hips (see Section 10 - Glossary for Hips).[/rule]

And there is the rub, and why the 10-foot markers are nothing but a guide and not definitive.
Title: Re: Track marks and our use of 10ft
Post by: Stony Hawk on September 06, 2016, 05:39:26 pm
Quote
as in a straight line run from the tangent of the inside boundary where the Skaters are.

This is the method I have always seen taught for proximity measurement in the apex for pack definition or EZ definition.

Agreed.   

That's too bad as the 'arc length' aspect of the geometry involved was the first time where I was able to use the published 7' 1/2" array measurement and get the measurements of the last poly segment to 'work out' in a symmetrical way.

I'll try again using 10' tangent lines to find the radius dimension that works.   I expect that its still not somewhere 'in the center'.

Title: Re: Track marks and our use of 10ft
Post by: Vanilla VICE on September 06, 2016, 07:30:49 pm
I deleted that post because I missed the rule that taco quoted, but yeah I still think that. :)
Title: Re: Track marks and our use of 10ft
Post by: llama of death on September 06, 2016, 08:11:25 pm
Quote
as in a straight line run from the tangent of the inside boundary where the Skaters are.

This is the method I have always seen taught for proximity measurement in the apex for pack definition or EZ definition.

Agreed.   

That's too bad as the 'arc length' aspect of the geometry involved was the first time where I was able to use the published 7' 1/2" array measurement and get the measurements of the last poly segment to 'work out' in a symmetrical way.

I'll try again using 10' tangent lines to find the radius dimension that works.   I expect that its still not somewhere 'in the center'.



A track with a 84.5" (or 7ft .5in) spacing [layout marks on the inside line], is parallel the inside line and is equally divided uses a 212.96 inch radius (or a 17ft 9in from center, or 5' 3" from the inside line).

*edit* It would have 6 segments of 10ft throughout the arc.
I have however tired this format on a track it does not look good to have the marks so close to the inside line. Better to add one more segment and increase the distance from the center to approximate the center of the track.
Title: Re: Track marks and our use of 10ft
Post by: Major Wood on September 07, 2016, 03:09:54 pm
I like full length lines partial lines, I don't find particularly helpful.

I'm not sure if this thread is going anywhere at this point. If you are finding the current workshopping of the track layout useful, I'm not stopping the conversation. I'm just pointing out that it seems like a lot of noise to me at this moment.
Title: Re: Track marks and our use of 10ft
Post by: Stony Hawk on September 07, 2016, 03:33:06 pm
Sorry Wood.  didn't intend to create noise.

I have nothing more to add
Title: Re: Track marks and our use of 10ft
Post by: SPECIAL EDwin on September 22, 2016, 10:32:41 am
There is one thing that nobody seems to have addressed in this thread and that is where skaters actually skate on the apex.  In my experience most of the traffic is not at the centerline of the track.  It's closer to the inside track boundary.  As Major Wood pointed out the only true indication of ten feet would have to be dots, not hashmarks.  ( in a perfect world there would be full track width hashmarks with a contrasting dot at the actual ten foot distance
)  When I lay out the track at practice I put the centers of two foot hashmarks about four feet from the inside track boundary because that gives skaters and refs a general idea of where ten feet is.  Lo and behold, that's where the skaters find themselves most of the time. Whether it's to cut short the lap length or because they know they can bridge farther out, skaters tend to hug the inside line rather than the middle ... and I've yet to see an apex jump on the outside line. So to my reckoning the track  design is brilliant.  It could be because it's what I "grew up with" but to me it's a very workable layout. OF course I tell skaters and newer referees how to USE the marks, that they are mere guidelines, and that we should all get a sense of distances (ten feet or twenty) independent of the lines on the track.  Sorry Llama.  Ain't broke, let's not fix it.  :)
Title: Re: Track marks and our use of 10ft
Post by: llama of death on September 22, 2016, 11:11:12 pm
When I lay out the track at practice I put the centers of two foot hash-marks about four feet from the inside track boundary because that gives skaters and refs a general idea of where ten feet is.

So... you yourself don't even use the WFTDA std layout then.

You modified it, similar to one of the methods I outlined in fact. By changing the marks from "center of track" to "4ft from the inside line" they are now parallel the inside line and a consistent distance apart. Assuming you stayed with the 7ft 1/2in measurement your marks are just over 9.29 ft apart. Adjusting the distance from the inside line to a distance of 5ft 3.5" would give very accurate 10ft marks all the way around the track btw.

**I do also agree that full lines and a dot would be ideal.**

So in what way, Special Edwind, are you saying "if its not broken don't fix it" if you also changed from using the standard layout?




@wood: I for one am enjoying seeing the various methods people have used to modify WFTDA std layout to achieve a usable marking system. Plus the more we discuss it the more likely this is to be perfected, and possibly gain traction in the leagues [seeing as they can vote and we cannot]. Skaters do seem to read this site from time to time. If the lack of progress one way or the other distresses you I would be amenable to locking the thread, but for the reasons above would prefer not to.
Title: Re: Track marks and our use of 10ft
Post by: SPECIAL EDwin on September 23, 2016, 08:45:33 pm
Ah yes, Llama, I was trying to fudge the recommended layout a bit, wasn't I?  What I meant by "not fixing it" was that I would rather deal with the existing method of evenly spaced but slightly incorrect hashmarks on the apexes than to make a change that would leave two spaces drastically different than the others.
 The idea of shortening the track to make the ten foot hashmarks center on the track would make the track fit into smaller venues,  but I still favor the original design. I do appreciate this thought-provoking exercise and your mathematical calculations.
Title: Re: Track marks and our use of 10ft
Post by: llama of death on September 25, 2016, 08:45:08 pm
Just a minor point of confusion, where did anyone say make the track shorter?
Title: Re: Track marks and our use of 10ft
Post by: SPECIAL EDwin on September 29, 2016, 11:33:24 pm
My idea, Llama. It would solve the problem of putting all ten foot marks on the center line, and I realize that this is a change that will never happen.  Again, I'm happy with the status quo.  As long as we all realize that there is a discrepancy, and understand the nature of that discrepancy we can still make good calls.
Title: Re: Track marks and our use of 10ft
Post by: llama of death on September 30, 2016, 07:02:04 pm
As long as we all realize that there is a discrepancy, and understand the nature of that discrepancy we can still make good calls.
Yes, though I find more and more that these good calls are being labeled bad calls because the skaters/fans/coaches do not know or understand these discrepancies. Which is most of the reason why I think it should be rethought, not just to make reffing easier (it wont really) but to make our calls more transparent to the viewer.

Title: Re: Track marks and our use of 10ft
Post by: SPECIAL EDwin on October 03, 2016, 04:36:02 pm
LLama, I don't know how feasible  this would be in other Leagues but we have been giving short classes to the skaters here ( in two local leagues) on this topic, including drawing a "lasagna slice" in chalk on the apex).   With your permission I will be using your calculations to illustrate what happens at the apex. I reckon it would be a good idea to mention something about it in captains meetings as well. Things may change in the future but that's how we are currently dealing with it. ... and I hope the fans will eventually catch on.
Title: Re: Track marks and our use of 10ft
Post by: llama of death on October 03, 2016, 07:25:48 pm
LLama, I don't know how feasible  this would be in other Leagues but we have been giving short classes to the skaters here ( in two local leagues) on this topic, including drawing a "lasagna slice" in chalk on the apex).   With your permission I will be using your calculations to illustrate what happens at the apex. I reckon it would be a good idea to mention something about it in captains meetings as well. Things may change in the future but that's how we are currently dealing with it. ... and I hope the fans will eventually catch on.

Yep, go ahead, just make sure your using the right one [wftda standard layout. etc] to match your track as I have posted quite a few images.