Measure All Splits Twice?

For years I, and many others, have been under the impression that since we are certifying only the overall distance, the splits need not be measured twice.

A measurer recently sent me a checklist he uses when measuring a course. I read it and told him “Contrary to your checklist, you are NOT required to lay out the splits on your first ride. Only those things that are to be certified (overall distance) need to be measured twice. This means that you can usually forget about your dry-run measurement.”

He replied that he was glad to read this, as he was being guided by the Course Measurement Data Sheet where it says "Use the first measurement ride to lay out the start/finish points and all intermediate split points."

This should be clarified in the measurement book, as it reduces the work by 1/3, which is to the good.
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Original Post

Good point. When I first started measuring, I did just that, laying out the splits on the first ride, then taking readings on the second. I would use Bob Baumel's computer program which computes the Sum Of Shortest Splits and use that to adjust the final distance. I'm fairly sure most of those course are a tad long.

That said, it can be a good check if there's any error in the overall course length, providing a possible clue to where the error occurred.
It is usually unwise to lay out splits on the first ride of a course. If it is done, and the same route is checked, there will be two measurements of a course, with splits. However, unless a miracle occurs the course will not be the right length, and it will have to be adjusted. This means that in addition to the overall length being adjusted, all the splits will need adjustment also, and documentation done over.

It makes more sense to measure until a course of the proper length is obtained, and combine the measurements into one complete measurement of the course. The second ride will check the length, and can also be used to establish split points in the knowledge that they will not need to be changed.

This means that the intermediate splits will not be certifiable, but the overall length will have been measured twice.

An exception to this is a pure out-back course, but these are not the usual type.

I believe this is what most experienced measurers do, but I am not sure whether the word is out to the newbies.

Our paperwork measurement examples do not appear to give a measurer this option. Commentary is invited.
I have always laid out splits on my first ride and then checked them on the second. While I understand Pete's system and reasoning, I am willing to risk the additional work needed to go back and adjust the splits in order to have the additional data to help solve a problem.

I remember measuring a 5 km course once where there was a big difference between the two rides. By looking at the split readings I was able to see where the problem was and I discovered I had turned one block early in the second mile in the second ride.

Either way works and I believe it is a matter of personal preference.
Paul,

I'd hate to do that on a marathon course. Three rides instead of two is a lot extra. I agree that having two measurements of the splits can be helpful, but usually, on the first ride, I have a bunch of non-split reference points instead.