Illinois state

Historian wrote:

How many of these "permanent monuments" are buried on the course? I recall seeing two - One at the mile and the second at the two mile. Last year was the first year the NFHS changed the measuring process to the "shortest distance" measurement. Prior to that it was the "center of the course", which is how I was told this course was measured in the past when it was questioned. Keeping the course as a traditional course for historical purposes makes sense, but I still question the accuracy of this course...sorry.

Our measurements were done in 2008, and I do not know if they dug up the mile markers to make them match the new SPR method. It seems unlikely, since moving the finish back 128 feet would be a problem. There isn't enough room to do it.

In 2008 the following points were marked with ~14 buried monuments:

The starting line on both ends.

The first turn in three locations around the turn.

The 0.5 mile mark, which is actually 13 feet short of the SPR 0.5 mile.

The mile mark, which is 34 feet short of the SPR mile.

The turn before the back loop in two locations.

The 1.5 mile mark, which is 94 feet short of the SPR 1.5 mile.

The 2.0 mile mark, which is 92 feet short of the SPR 2.0 mile.

The 2.5 mile mark, which is 110 feet short of the SPR 2.5 mile.

The Finish line on both ends, which is 128 feet short of the SPR 3.0 miles.

All other turns are marked by trees, most of which have been there since 1971.

According to the old NFHS middle-of-the-path method of measuring courses Detweiller would measure almost exactly 3.000 miles if the path width was assumed to be 12 feet wide, which is a reasonable assumption.

Detweiller is probably the most precisely measured cross country course in America. I will try to find out if they changed the mile markers.

The course is substantially wider than 12 feet at it's narrowest stretch. I completely agree that using the old MOC method gets you close to 3 miles, and that is what some of the mid pack runners will actually run because the SPR is taken away because of the mass of runners in the race. The top runners should be able to run the SPR if they are focused, and that distance in my opinion (based on my measurements) is substantially less than the 42m short that you mention.

Historian wrote:

The course is substantially wider than 12 feet at it's narrowest stretch. I completely agree that using the old MOC method gets you close to 3 miles, and that is what some of the mid pack runners will actually run because the SPR is taken away because of the mass of runners in the race. The top runners should be able to run the SPR if they are focused, and that distance in my opinion (based on my measurements) is substantially less than the 42m short that you mention.

How did you measure the course?

And what measurement did you get?

I forget the exact distance and the exact Trimble GPS model I used, along with a gear driven metric survey wheel . I walked the course two times each (four times total that day), using both measuring methods and wearing the Trimble in their old school yellow back pack while pushing the wheel. I was shocked that the course was as close to three miles as it was while using the MOC method. For the second method, I recall measuring in a worn trail/rut on some turns, and not measuring closer to the inside line/fencing in those same areas where spectators were present taking away these inside tangents, but did wheel on the inside line in low spectator areas where I noticed some athletes "working the line" in these areas during the race. So I basically measured what I predicted the top runners could possibly come up with for "their" SPR (not what is the protocol by USATF for road race certification). Measuring using this method (and what is now the current method) I recall a number that was much larger than what you mention, and one that made many people angry with it.

Well I don't angry. I get accurate.

This is what we did. All using the SPR method.

Miles : Method

2.9758 : Steel tape - gold standard

2.9717 : Bicycle with a Jones counter calibrated on the grass

2.9727 : Garmin Edge 305 GPS on a bike ~9 mph

2.9808 : Garmin Edge 305 GPS walking ~3 mph

2.9502 : Walking Wheel - expensive uncalibrated, probably similar to the one you used

2.9568 : Walking Wheel - inexpensive Home Depot model uncalibrated

The problem with walking wheels is that they slip, so their measurements always come up short. Very short. The only way to get a decent measurement using any wheeled device is to calibrate it against a steel tape on the grass surface of the course. Even when we did this for the bike with a Jones counter, the measurement still came up short.

The problem with GPS devices is the interaction between location uncertainty versus the sampling frequency around the turns. The slower you go the more the location uncertainty adds up, and you end up measuring long. The faster you go, the more you truncate the turns, which ends up measuring short. increasing or decreasing the sampling rate will reduce the error on one of these, while increasing the error on the other.

Neither of the methods you used is as accurate or precise as using a steel tape.

You guys have a distance dynasty in Illinois and even the men measuring the course treat it as such. Amazing effort put in by those handling the course! My state these course directors say their footsteps equal so many meters so they walk the course counting their steps for god sake. Might go to Footlocker just to watch J. Davis of Illinois run. He's not doing NXN is he?

Neat study.

Why didn't you calibrate the "Walking Wheels" ??

Your slippage comment is interesting, especially since you mentioned how to take that possible "slippage" into consideration.

What tension was applied to the steel tape in your process?

How was the tape tensioned on the turns?

What was the temperature at the times of the measuring.

You may be right on your last statement if YOU and YOUR crew used the steel tape properly. However, the facts remain the same with my measurements: One process resulted in a substantially longer distance than the other, and the times always indicate that the kids running that course are getting that benefit.

armored wrote:

You guys have a distance dynasty in Illinois and even the men measuring the course treat it as such. Amazing effort put in by those handling the course! My state these course directors say their footsteps equal so many meters so they walk the course counting their steps for god sake. Might go to Footlocker just to watch J. Davis of Illinois run. He's not doing NXN is he?

Are you thinking of the UW-Parkside course? What kind of time might he run on a course that is almost 5k?

Spork wrote:

When I ran there, I didn't know anyone who trained through the winter. I'm sure York boys did, and so did people like Pat Joyce and Len Sitko (on either end of me age-wise). Now that I live in LA, it'd be weird to stop running after XC was over.

Not from York. I ran doubles all winter all 4 years 78-82. Walked the mile to school at 5:45 am to get in the first one. Often had hockey practice after the second one for my third workout of the day. And, still could only just barely break 4:30 for 1600. No accounting for a lack of talent.

Anyway, the best runners in my south suburban conference all ran winters.

His official time was 13:59.3, The IHSA has 14:00, as they don't do decimals this year for some odd reason. His verified time, and the time that they announced was 13:59.3.

That's very interesting about the distance of the course. I'll have to look into it.

Reboot runner wrote:

Anyway, the best runners in my south suburban conference all ran winters.

Me too. :-)

I guess this is one way of saying that I didn't hang around the best runners :). I did well in regionals, but only because talent was way down.

It's hard to convey what running was like pre-Internet. I just assumed people at York and Stagg etc. had superior coaching. And better genes. They did, have at least the former, but they also put in a ton of miles, year round. Much more than I'd ever have thought of doing. I suppose that comes back to coaching. It wasn't until much later that I realized you shouldn't spend half your season getting in basic shape.

Ran at York. Hardly trained from mid Nov through mid Jan back in the day before Nike nationals. Needed the rest. Same with the rest of my teammates absent a few less talented guys.

When I was running in the MSL (NW suburbs), we all got a week off after xc and a week or two off after outdoor. Trained the rest of the year.

I think the pancake flat landscape is as much of a disadvantage as the winters. We did plenty of brutally cold and windy workouts running up and down the neighborhood streets right by the HS, but only in IL can the incline into the finish at Detweiller be called a hill.

Also want to give a shout-out to Evan Jager-- another IL prep great.

Historian wrote:

Neat study.

Why didn't you calibrate the "Walking Wheels" ??

Your slippage comment is interesting, especially since you mentioned how to take that possible "slippage" into consideration.

What tension was applied to the steel tape in your process?

How was the tape tensioned on the turns?

What was the temperature at the times of the measuring.

You may be right on your last statement if YOU and YOUR crew used the steel tape properly. However, the facts remain the same with my measurements: One process resulted in a substantially longer distance than the other, and the times always indicate that the kids running that course are getting that benefit.

So you gonna try to out-geek the group that went to Detweiller to get the truth? Never gonna happen. But please continue to try to point out holes in the methodology. It's that kind of discipline that led to the measurement meeting in the first place.

Years ago I saw Derrick and Havel coming up the ranks in Illinois and I figured they might beat Virgin's record, so I went on Dyestat and asked about the course length. Everyone "knew" something about it, but when I asked how do you "know", I found out that no DID really know how long the course was, and people got really angry when I kept pointing that out. All the data was based on walking wheels and a couple of experts told us we couldn't trust those. Myths die hard.

The On Course Ratings Systems guys from Virginia were monitoring the discussion and they wanted a chance to get an official measurement of the legendary Detweiller course. So we all went and measured the course in every way we could think of to separate fact from myth.

We didn't calibrate the walking wheels on grass because we knew no one else did when they used theirs. Besides, when we finished, we had our calibration factor, but it would be unreliable no matter what factor we used. We did calibrate the wheels on pavement and they were very accurate on a smooth surface.

The group that measured the course is called On Course Ratings Systems. They used a hand held scale to put the required tension on the tape for the straights. They measured out a 1 foot radius on the turns and laid the tape on the ground without tension. The temperature was about 85 F that day, and I remember asking about the heat effect on the tape, and they knew all about it, so I am assuming they took that into consideration.

But let's assume they didn't. The coefficient of expansion for a steel tape is 0.0000116 per unit length per degree Celcius. Let's assume that the tape was calibrated at 20 C, and we measured on a 30 C day. The expansion would be 2.9758 * 0.0000116 * 10 = 0.000345 miles. That's 20 inches! So 2.9758 miles +/- 20 inches. Go ahead and throw a few more inches in there for the turns if you want.

Steel tape, or composite tape is the gold standard no matter how you look at it.

The guy who measured the course using a calibrated Jones counter on the bike is certified by the USATF to measure courses, and has done the Chicago marathon among other high profile courses in the Midwest. He spent half the day calibrating the counter before and after every measurement.

Unfortunately the results you got were unreliable because both the GPS and walking wheels are not precise enough. I feel your pain. I was the one who measured the course with one of the wheels and the GPS, just like you did.

TannerD22 wrote:

His official time was 13:59.3, The IHSA has 14:00, as they don't do decimals this year for some odd reason. His verified time, and the time that they announced was 13:59.3.

That's very interesting about the distance of the course. I'll have to look into it.

The official results are always rounded to the nearest second for almost all the times, but since they went to FAT, we can usually get the more accurate times from the raw data. In the 1970's they showed the winning time in tenths of a second, but all other times were rounded to the second.

There are a couple of top ten times that appear to be rounded to a second which presents a problem for us stat geeks. Is Davis' 13:59.3 faster than Torres' and Spivey's 14:00? Do we use official rounded times or the FAT times which we know are more accurate?

Are we really going to start adding 0.24 seconds to hand timed XC races?

Yes... we ... are.

Just trying to verify the process that was used. So a crew went out there in the summer when the course was not set up and tried to measure the course? Have you calculated the difference from the precise all day measuring process, to that of the least accurate devise you used? All methods come out very close considering the chances of measuring the exact same route each time is practically impossible. Since there is plenty of room for course set up/measuring error on determining the 30cm positioning on the turns, especially when trying to ride a bike that precisely with out a lined course I think you are missing the point in course measurement. Sorry. Lastly, I believe USATF uses a short course calculation factor for your bike method. Was that taken in to consideration in comparison to the steel tape measurement?

Historian wrote:

Just trying to verify the process that was used. So a crew went out there in the summer when the course was not set up and tried to measure the course? Have you calculated the difference from the precise all day measuring process, to that of the least accurate devise you used? All methods come out very close considering the chances of measuring the exact same route each time is practically impossible. Since there is plenty of room for course set up/measuring error on determining the 30cm positioning on the turns, especially when trying to ride a bike that precisely with out a lined course I think you are missing the point in course measurement. Sorry. Lastly, I believe USATF uses a short course calculation factor for your bike method. Was that taken in to consideration in comparison to the steel tape measurement?

Myths die hard, but I have experience killing this particular myth. People just don't to let go of their conclusions, especially if they've put their own sweat into them and have defended them in heated arguments in the past, which you have done.

Yes, we measured in the summer after recreating the course using the monuments. That is exactly how the course is recreated every year. We are familiar with the course and it's a well marked course, so there really wasn't any uncertainty about where people were running. Also, the mile markers other than the 1.5 mile marker all came up short by fairly steady increasing amounts as the course went on. This is exactly what you would expect when converting from a middle-of-the-path course to SPR.

I don't understand your second question.

It is fairly easy to follow the same path within a reasonable margin of error. No doubt riding the bike tightly around the turns would introduce some error, but that error would be small compared to the final results we got.

Yes, USATF uses a short-course correction, which means they do their absolute best to mark the stated race distance and then add a few meters to it to make sure that if someone sets a world record, the course won't come up short when someone else comes in to verify the record. Why do you bring that up? It has nothing to do with this discussion. We aren't trying to create a perfect 3.000 mile course. We were trying to get the most accurate measurement of the existing course. It's like telling the guy who comes in to verify a world record to make sure they take into account the short course factor. They don't care. All they care about is if the course is at least as long as the stated length.

I think I've stated my case clearly and backed it up with rock solid data from credible sources, yet you say I'm missing the point of course measuring. Please explain your philosophy more clearly and explain what we missed. Are you saying that you still trust your results over the tape measurement?