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It is confusing to the general public and, for the most part, arbitrary.

Courses could be measured to the actual distance, and validated if the course proves to be at least 99.9% of the stated distance.

An American record from an old course (current certification process) could only be broken on a new course if the time run is at least 0.1% faster. It's unlikely this would ever be an issue since American road records are almost always broken by more than that.

It's been quiet on the board lately, so I thought I'd rattle a few cages. Smiler
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Here we are prisoners of history.

In the 1970’s and early 1980’s Ken Young was the keeper of records for road running. He called his operation the “National Running Data Center (NRDC)". He recognized a need for course certification to assure the credibility of road running records. The criterion he used was that a record was valid if the runner ran no less than the nominal distance and the recorded time was no more than the existing record.

Ken and Ted Corbitt worked together. Ken produced a newsletter “NRDC News.” In it he, with wife Jennifer, included recent records, articles related to records, and – important from our point of view – a list of certifiers and how to contact them. NRDC News was the only communication vehicle available to the early certifiers.

When NRDC was preparing to become the official TAC (now USATF) records-keeper for road running, Ken and Ted decided that in order to keep too many courses from being found short, a bit of length needed to be added. 1 m/km was decided, and Ted declared that this was required for all courses certified after 1982. All courses certified before that time were decertified.

Since that time the SCPF has become part of the course layout procedure all around the world.

This approach worked well for the records people, as now most courses pass validation.

However, it is a thorn in the side of many people who believe that the SCPF is confusing and illogical. As a measurer I don’t like it myself, although I understand the logic behind it. I’d prefer an approach as described by Mark, but can’t see how it can be achieved. It would require a fundamental change in record-keeping philosophy.

If people can’t understand why a course should be laid out a bit on the long side, would they be better able to understand why a record should count if run on a short course?

In the immortal words of Yul Brynner, “Is a puzzlement.”
Last edited by peteriegel
If people can’t understand why a course should be laid out a bit on the long side, would they be better able to understand why a record should count if run on a short course?

If people can understand why sprints with a tailwind and road runs with a net elevation drop still count as a record, I don't think they'd have a problem with a 99995 meter 10k. But maybe you're right.

I also don't think we are a prisoner of our history because much bigger changes have been implemented in the past, such as decertifying all races before 1982.

But your point about it becoming part of the course layout procedure worldwide is a good one. We ARE a prisoner of the IAAF.

I meant to put this in RRTC Topics. Can you move the whole thread?

DONE! Pete
Last edited by peteriegel
I believe that the SCPF is a better idea than allowing records to stand on a course that was less than the desired distance.

I started to make my case, but as I typed, I concluded Mark has a point regarding records being broken by more than a second or two. If that is the case (and I have not checked to see otherwise), then my point for keeping the SCPF is simply to make sure the record was set on a course that was at least the specified distance. If we allow short courses to be record-eligible, we degrade the value of the record, even if the course was only a few meters short. Integrity.

Therefore, I think that if word got out that a record could be set on a course that was "not quite" long enough, there would be little incentive for courses to be certified, sending us back to the dark ages when people used pedometers and car odometers to set out their course. Then, someone's "PR" would be devalued. I think we would be creating the gray zone we are currently trying to avoid.
I have heard there is an RD in NY who measures his courses following all RRTC procedures, with the exception of using the SCPF. His feeling is he wants his courses to be exactly the distance advertised, and not a cm over.

Any qualms I had about SCPF were assuaged by Pete's excellent analogy many years ago of it being the equivalent of adding a single card to a deck of 52 - actually, it would be more like adding a card to a casino "shoe" of several decks (although I wouldn't know firsthand Wink )

I think we can both agree that the only real issue here is one of public perception. There is of course, always a grey zone that's unavoidable. But as long as everybody is competing and trying to set records on courses that are measured in the same way, it doesn't really matter if we center our measurement variation on those courses about 10000 meters or 10010 meters, as long as we do it the same for every course.

Whenever a measurer is asked about how he measures, the topic of the SCPF often comes up. People are interested because the SCPF affects the course they are running. You are making their time slower, nevermind by a negligible amount. If we simply measured the course to be as close to the stated distance as possible, the topic of course distance variation would almost never come up. Almost no one would be aware that a certified 10k could actually be anywhere between 99990 and 10010 meters long. And that's good, because that fact is essentially irrelevant to 99.9% of runners.
This thread is similar to the discussion on Validations. We used to allow a record set on a course less than the distance(within .05% of the distance). However, that has changed and now it must be at least the distance.

I feel that we must use the SCPF as some have stated. The extra distance is our safety factor and has proven to be a good thing.
The best argument in favor of the SCPF, especially in the USA, is that USATF allows ANYBODY to measure a course for certification. No particular training or credentials are required.

I suspect if we required all courses to be measured by trained, experienced, and credentialed measurers, the SCPF could be reduced or eliminated. We've chosen not to do that in an effort to spread the certification "gospel" and get more races run on certified courses.

Between that and the inaccuracy inherent in a method that usually depends on the changing diameter of a pneumatic tire, some form of "insurance" is warranted. The SCPF provides that.
Courses are not made more accurate by including the SCPF. They are simply made longer, and in fact less accurate. We are sacrificing accuracy in the name of "thou shall not be short."

In addition, I think the SCPF, and its reason for being, fosters the belief by some that the USATF doesn't really care if a certified course is accurate, only that it is not short. I have heard that, or something similar, said more than once on other message boards.

Ah, but are we absolutely positive every course is too long (longer than the advertised distance) if a runner follows the shortest possible route? Did the measurer follow the SPR for the entire course?

You, I, and everyone else reading this forum would put any of our efforts out there for any to validate, fully confident that our course would stand up to scrutiny. It is, however, as Jay points out, those who do not measure courses as a business/hobby that need to have the SCPF included.

I have measured with co-measurers, and I am consistently measuring shorter for a given course than they measure, indicating I have ridden a shorter route through curves than they have. The SCPF is very valid for new measurers to use.

You could rightly argue that experienced (5 courses, 10 courses?) measurers should not use the SCPF, since they presumably are accurate in their judgment of SPR. I could buy into that argument. Then you would have courses that were within a meter or two, at the most, of the advertised distance. In a marathon, that would make a difference of a few seconds to 10 seconds to most runners, as marathon courses are currently 42 meters long. A valid argument about the course being artificially long for the marathon, but nearly inconsequential in a 5k.

As it is very rare that anyone validates any of our courses (meaning my courses are not validated by anyone), do we each know for sure that we are accurate for all of our courses? Or, might some of our courses be shown to be short if 5 other measurers checked each of them? I firmly believe all of my courses are correct, but have no way to prove it without someone else measuring a few of them, and verifying my Cal courses. All I can do is say "I am confident they are all accurate, as I have followed procedures to a "T". Thus, the SCPF has value.
For what its worth, the Guido Brothers consider ourselves an experienced measurers and we like the confidence that the SCPF and the "at least the advertised distance" provides. As Duane notes, following the shortest path isn't always easy. I is easy to miss coming off a tangent by a little. Its also possible to mis-judge the tangent points on a long tangent. If there are cars parked along the shortest route or there is traffic that causes off sets, more uncertainty is added. Add to that the "anyone can measure" approach and the SCPF becomes even more valuable.

You may hear whining about the SCPF (especially from the GPS crowd), but imagine the outcry that would result if a few courses were found short. Our reputation would be badly damaged and confidence in "certified courses" would disappear.

We vote for keeping the SPCF.
I think some of you are misinterpreting my argument. I'm not saying that the SCPF is not necessary to ensure a 10k course is at least 10000 meters. I'm arguing that there shouldn't be anything sacred about being absolutely sure the course is not less than 10000 meters.

When we measure courses they are, in all likelihood , somewhere between 10000 and 10020 meters long. If we eliminated the SCPF for all courses then they would all be somewhere between 99990 and 10010 meters long. So what? Everybody would still be competing against each other and trying to break each other's records on courses that were all the same distance (at least to the accuracy level we can provide).

It just makes more sense to me to measure courses so they are 10000 meters, plus or minus 10 meters, than it does to measure courses so they are 10010 meters, plus or minus 10 meters.

Speaking of experienced measurers, isn't it odd that we have set up a situation where, as a person becomes better and better at measuring, he probably becomes less and less accurate, since he is getting closer and closer to 10010 meters. Inexperienced measurer's courses are probably closer to actually being 10000 meters in length.
Our goal is to have a course "at least as long as the advertised distance". What is to prevent an experienced measurer from determining that his measurement truly did follow the SPR, and removing the SCPF from each of the mile points, and the overall length, thus yielding a course that is within a meter of the advertised distance?

If we still invoke the SCPF in our procedures, but I know beyond a shadow of a doubt that my measurement is 5001 meters, what is to prevent me from adjusting my locations and the Start or Finish to reflect the true length, disregarding the SCPF? I know my course will stand up to validation, which is the goal.

Conversely, if a race director says they are having world-class runners, you leave the SCPF intact for that measurement, even if you feel you have measured the SPR. That way, if the validation team has a long Cal course, your course will still stand up to validation.
Why not measure it using Google Earth or Map my Run? Then make up plausible numbers. You'll be close and nobody but you will know.

We rely on trust. Could be you'll be tripped up by a fast oldster whose run requires a validation. Then cross your fingers.

I've caught some liars, but not lately.

A standard 10k is laid out at 10,010 meters, just as a standard track is laid out 30 cm from the curb. If the runner runs 20 cm out, is he running a short course?

This is angels on pinheads. The extra distance is trivial, and it does the job it's supposed to do. In the early days the SCPF did not exist as such. It was simply mandated by Ted Corbitt that an extra meter per kilometer should be added to all layouts. It was only when it was built into the constant that it became known as the SCPF.
Our goal is to have a course "at least as long as the advertised distance".

That is what I am fundamentally taking issue with. Our goal should be to have a course "as close to the advertised distance as possible."

As far as the actual distance difference goes, I agree this is angels on pinheads. This is all about public perception. And having a stated goal which does not have accuracy as its main thrust, creates bad public perception.
For me, the real purpose of the SCPF is to establish valid courses – not courses that are more accurate. ‘Accurate’ can be either exact or almost exact. Almost exact and less than the desired distance cannot be validated, per our standards.

I believe that there is something sacred about establishing a 10K that is minimally 10,000 meters in length. If our method can be improved in order to measure closer to 10,000 meters while maintaining a high percentage of passing validations, let’s do it – but, while eliminating the SCPF in order to get that 10K close (+ or -) to 10,000 meters may improve accuracy, it does not improve validity. With validation as the goal, the distance demands respect and shall not be short.
I believe that, some time ago, I read through a set of data on this board that showed a sudden and notable improvement in the percentage of courses that passed validation. Pete mentioned early in this thread that since the SCPF was added in 1982, most courses now pass validation. Considering this, we are not creating course that are unnecessarily long – they are measured 'too long' in order to improve the validity of courses. For those of you that have performed validation rides, how close are you coming to the actual distance? Dangerously close? Or maybe .0009% above the distance?
Currently, what are the most common reasons that a course might fail validation?

I was not advocating removing the SCPF, if that was how it came across in my post. I still use it for every course.

I was just saying that if someone did remove most of the factor, if they knew their course could not be short, that is up to them, understanding it may be called into question if ever validated.

I don't want anyone to question the integrity of my courses, so I will continue to use SCPF. That is the standard that we measure to.
Of course I wouldn't eliminate the SCPF without also changing the validation requirement. If we eliminated the SCPF a 10k course would still be eligible for records if it was found to be at least 9990 meters on validation. A system like that would "work" just as well as the current system in the sense that the same percentage of courses would pass validation.

A lot of people get hung up on the idea that we would allow a record to be set on a course that is slightly short of the advertised distance. But we allow records to be set on courses with a net elevation drop and on courses with a net tailwind. Those things provide a much bigger advantage to a runner than a course that is 5 or 10 meters short.
But we allow records to be set on courses with a net elevation drop and on courses with a net tailwind.

Not entirely true - the various alphabet bodies of record-keeping won't allow records on courses w/ extreme separation or drop.

Mark, you seem to be concerned with public perception. In my experience, very few people know what the SCPF is, or care very much if they do. Heck, few even know what "certified" means (many, even race directors, confuse it with "sanctioned.") A lot more people get pissed off over automobile-measured courses that come up way short than those which are a few meters long due to SCPF. For a serious runner, certification is just a "Good Racekeeping Seal of Approval," and they don't care about the details of how that's achieved.

I'd be very wary of changing something as established as SCPF. IMO we'd be creating two levels of courses, pre- and post-SCPF elimination. A similar situation occurred back in the 80s when SCPF and SPR were instituted - many records, most notably Salazar's "WR" in NYCM, were tossed, and the confusion and some bad blood lingers until today (I'm sure Fred Lebow went to his grave cursing the RRTC edict that took away that mark from his race).

Are we to go back and retroactively award records to runners who came close on courses that used the SCPF? I recall Deena Kastor missing the 8K AR and a big bonus by 2 seconds on a course I'd measured on Randall's Island. If she had gotten it, I would have sweated bullets awaiting the validation, knowing that a good portion of an athlete's income hinged on my accuracy. The SCPF lets me sleep a bit easier.
The old misapprehension surfaces again.

When Alberto Salazar ran his fine race in 1981 at New York it was widely hailed as a new “world record.” However, at that time there were no road running world records recognized by any governing body. All road records were “media records.” Salazar never had his "record" disallowed - it never existed as a USATF or any record recognized by any governing body.

When USATF began to absorb road running into itself in the early 1980’s, records were seen as an essential part of the mix. Some of Ken Young’s “records” were accepted as USATF records. Ken had arranged for validations of these records.

The marathon did not have a USATF record at that time. I recall that NYC was called upon to cooperate in such a validation, but that there was some difficulty in setting it up. Finally, USATF said that a validation had to be held within three years of the race or all bets were off, and the Salazar run would never receive consideration as a record.

Tom Knight performed a validation measurement in December 1984. He considered various options for the proper path (one foot from curb, one meter from curb) as standards were still in a state of flux. All Tom’s measurements showed the course to be short of the marathon distance.

The USATF Records Committee had to decide whether to recognize the Salazar run as a record, and decided not to, in spite of the fact that the run had been widely recognized by most media as the “world record” for several years. This decision, while technically defensible, was viewed by many as a travesty of justice, and RRTC received its share of opprobrium for its heartlessness.

It's interesting to note that most of the blame over the injustice to Salazar was laid at RRTC's feet, while no one criticized those who provided the short course in the first place.

The annual broadcast of the New York City Marathon continued to credit Salazar with the American record, even after Pat Petersen (who was a member of the New York Road Runners Club) ran faster at London, and was recognized as the US record-holder.

Since the big controversy over the Salazar run, every new marathon record has been validated, either before or after the fact.
Not entirely true - the various alphabet bodies of record-keeping won't allow records on courses w/ extreme separation or drop.

I'm not talking about an extreme separation or drop. It takes very little of either to make 2 seconds difference in a 10k. If we're going to be so concerned about a 10k race being validated at 9990 meters, then we should be at least as concerned about allowing ANY net elevation drop.

In my experience, very few people know what the SCPF is, or care very much if they do.

You're right. Most people have no clue what we do and don't really care. They also wouldn't know or care if we eliminated the SCPF. But there are some who are aware of our methods who interpret the thou-shall-not-be-short doctrine and the SCPF as evidence that the USATF doesn't care if the course is accurate, as long as it is not short. That's come up a couple times on the LetsRun message board.

Are we to go back and retroactively award records to runners who came close on courses that used the SCPF?

If someone runs a time on a no-SCPF course that is more than 0.1% better than a record set on a SCPF course, he gets the new record. Once that happens, he holds the record until someone runs a faster time on either type of course.

You might say that it's not really fair to the person who runs on an SCPF course later and comes within 0.1% of the record time. But we don't worry about that kind of stuff now. In the current system, if an existed record was set on a course that was validated at 10012 meters, and then later, someone runs 1 second faster on a course that is validated at 10002 meters, we still give the second runner the record, even though he didn't really run faster?

The SCPF lets me sleep a bit easier.

You'd sleep just as well if the SCPF was eliminated and the validation requirement was set to 9990 meters, because your margin of error would be the same.

You are preaching to the choir. Many measurers, myself included, would prefer that we measure things without SCPF. When I started running there was no SCPF, and the purpose of a certified course, to me, was to give me a tool which I could use - with my personal watch - to assess how I did in my various races. Records never entered my mind.

The official reason we are part of USATF is as a support group for the Records Committee. They decide what the criteria are for records. We don't.

I'm not aware of any open forum for USATF record-keepers, but that would be the place to agitate for a change of this type.

Until the Records Committee decides that the SCPF is no longer wanted, we will have it. Considering that it is in place with IAAF and the rest of the world, I expect it is here to stay.
The SCPF is a good system. The data quoted above shows that it has kept many courses from being short.

I like it, it makes both logical, political and mathematical sense for a method to insure that we are not certifying courses are short.

There is NO WAY that a person on a bicycle can actually ride the mathematical shortest course, no matter what his perceptions of his bike handling skills might be. This is because to keep a bike upright you have to turn towards the direction of your fall. Therefore even if you 'feel' you are riding a straight line, the actual course ridden is never exactly straight, and even less so on windy days.

How many times have your post measurement calibration rides not EXACTLY matched your pre-measurement rides? And that was on an ideal, short and straight bit of road!

The method, with SCPF, is as close as we can come to providing a course that is 'not less than the advertised distance'. Why do we aim for close but 'not less'? Because it is just impossible to be exactly right, and so by trying to get closer we run the risk of even more courses being later found to be short.

If you are that worried about the inches, then make sure your start line is wide enough for all the runners to stand on it without having to stand behind another runner. Oh, a few hundred yards wide should do. Make sure your line is at a slight angle so that they are all are an equal distance from the tangent point on the first turn, and then paint a blue line down the length of the shortest course, getting all the tangents right.

I think that more importantly than the SCPF, in reality the exact path the lead bike takes has more to do with whether the first runner does the advertized length or something more.

Our system gives what you could call the runners Kilometer: 1K plus SCPF. (+ or - bike wobble, wind wobble, path error, curb distance error, heat variations, parked cars etc.)

It is still one of the most accurately reproduced non-linear measurements, and it is quick, cheep and above all - reproducible.

Our County offices once had an exact 100' calibration set out for local land measures to bring in their steal measuring tapes to have them validated. Some failed. How accurate is your tape? It is probable that if we were to go out and measure, with a laser beam, every calibration courses used, we would find enough errors to quickly send us screaming back into the church of SCPF. That's without going and actually validating many courses.

I like the graph posted above, but would like to know, what percent of courses would have failed validation if the SCPF were not used. (i.e. even with SCPF x% are found short but if SCPF were not used than y% would have been found to be short)

Peat, could you present the data to show how many or what percent failed, and how many would have failed if the SCPF were not applied? (i.e. when it is subtracted would have put them in the failed category.)

In the end, you have to remember that the validation ride may also not have taken the shortest course. A runner who is out in front, and who has a clear view, may run a better line than we can bike. When going around a curve, how close to the curb can you run, compared with the bike measurement distance?

SCPF is to allow for our errors, and to give the record setter a good chance that his record will stand. Without SCPF there would be a lot more elite runners who would be very pissed off with us, because more courses would fail validation. Better to a little over the distance than to ruin an athletes record setting best. Some of you may think you are measurement gods who never err, but personally I would not want that responsibility on my shoulders.
Mr. Reigel, JamesM just called you a piece of dirt!!! ("Peat")

James, I don't think any of us consider ourselves "measurement gods". We bring up topics for discussion when we may feel we have become complacent, or feel the need to re-evaluate a process. Maybe it is because new technology has become available since the measurment practice began (electronic measurement, Web, software). Or, it could be someone felt there may be a better way to do something. It is good to question any process occasionally. Sometimes new techniques arise; other times the old technique is determined to still be the best. Better to question methods than to mindlessly follow. We understand the entire process better when methods and reasons are discussed. No need to call Mr. Reigel a piece of spongy matter. Smiler Or, to call Mark conceited, since he started this thread.
Below is a summary of validations performed in the years 1987-2006. Note that "Remeasured Length" is shown in actual meters without SCPF.

Depending on whether we use the nominal length as the acceptance cutoff or allow a negative 0.5 m/km we have a pass rate of about 90 percent.

If we eliminate the 1 m/km SCPF and lower the acceptance level by the same amount, no effect is seen on the number of courses passing validation.

If anyone wants the Excel file containing all of the data on which this is based, it may be obtained at:

Last edited by peteriegel

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