With enough speed on a rollatape wheel, errors can be minimized, but not eliminated. The problem is, when contact with the ground is lost, the wheel decelerates, so on a course with differing terrain, it will consistently read less than the actual distance. Weaving about can actually make the difference up, oddly.
I saw the OCRS thing two years ago and preformed the same tests, but came with different results than the guy.
Walking on grass, I would get good numbers.
Jogging on grass, I would understate the distance.
Walking on the track, I would overstate.
Jogging on the track, I would get good numbers.
Numbers were consistent when I tried it on a local cross course. I used a steel 75m tape, measuring out 50m at a time, the wheel, witha jog would measure about 98-99m for every 100m.
I don't really concern myself with these things. It's nice to know the course distance, but precision in the matter is beyond me.
Further, I have yet to hear an explanation for the second part of the OCRS protocol, that is, assigning a number for the "course difficulty".
The guy went through all that work to measure courses with high precision, and then assigns an arbitrary number to the course for "difficulty"? WTF?