NYTimes article on measuring out the marathon course

oh no. wrote:

so is it safe to say that you are always going to run a little (very little, i realize) farther on a certified course assuming you are not going to be able to take that perfect line and with a .1% added?

Fair question. No, it isn't safe to conclude you'd run a tiny bit further...as counterintuitive as it appears. Here's why: Example- there's an approx one mile stretch of the Detroit Marathon that uses Michigan Ave (a road that stretches all the way to Chicago). It's like 7 lanes wide w/half of it being concrete & 1/2 brick. Both surfaces have cracks, potholes & traffic plus it bends subtly to the left half way to the next turn.

I'll be going from the right to the left, following as best I can a one mile long tangent. The .1% added to calculations could, I repeat, could get easily eaten up trying to follow what I think is the SPR during that mile. I really don't know what portion of the .1%, if any, would be used. But, having it in there, using this extreme example, goes a long way toward ensuring a stretch like that comes out being long enough. If the approx mile stretch had been straight, I probably would be adding about 5' to that measured section. Courses in 99%+ of cases ain't straight tho.

David, I'm sure Paul Milvys' spirit was following along.

Nice article and a big thank you.

So Scott, given the admitted inaccuracy of your measurements, don't you agree that something as important as the US Marathon trials should be run on a 400m track?

hehe -- thanks for the work of all you guys -- a very interesting article.

Running in Circles wrote:

So Scott, given the admitted inaccuracy of your measurements, don't you agree that something as important as the US Marathon trials should be run on a 400m track?

hehe -- thanks for the work of all you guys -- a very interesting article.

Maybe your screen name should be "Devil's Advocate" ;-)

It's not a question of accuracy, it's precision. Think about when you are reading a tape measure or ruler. If it was absolutely essential that you measure something to be AT LEAST a certain distance, you'd probably mark or cut a hair on the long side, just to take into account that the end of the tape might not be exactly zero or that the markings are slightly off. That's essentially what the 1.001 SCPF is for - it's about as accurate as it's been determined that humans can measure, given limitations of equipment, dodging traffic, changing road srufaces (you'll get a different reading if you calibrate on rough asphalt and measure a stretch on smooth concrete). At the worst, you'll have run an extra meter every km, at best, you'll run at least an honest 1,000m.

Very interesting. Of course, don't stress about it too much for my sake if you're ever measuring a course I'm racing -- an extra meter or two isn't going to keep me from a WR!

So given all of this, imagine that there is a perfectly-paved stretch of I-75 that stays perfectly straight for well in excess of 27 miles. If God (or whoever you're willing to believe is perfect) gave you all the time you wanted to map a 100.000% accurate point-to-point marathon course, how close would you expect to get? .1%? Closer?

JimG wrote:

it's about as accurate as it's been determined that humans can measure

I should have said "precisely" rather than "accurate"

Running in Circles wrote:

So given all of this, imagine that there is a perfectly-paved stretch of I-75 that stays perfectly straight for well in excess of 27 miles. If God (or whoever you're willing to believe is perfect) gave you all the time you wanted to map a 100.000% accurate point-to-point marathon course, how close would you expect to get? .1%? Closer?

Let's say we get 10 IAAF Level A measurers to measure this I-75 straight, flat marathon. Chances are slim & none any of the 10 would wind up w/the same finish line. Chances are very high they'd be mighty close to each other though. What to make of this...we're human and error.

For those who'd like a puzzle and don't measure, of those 10 different stopping points (or finishes), which would be the one best suited for certification? The shortest, middle, longest or average?

PS We could almost pull off this experiment along M-28 in Michigan's Upper Peninsula between Seney & Shingleton since there's a 23 mile straight, flat section. The earth curves so you can't see the end. Further trivia...back in the day, a marathon WAS run along that stretch w/the requisite extra distance tacked on somewhere (the start probably).

scotth wrote:

For those who'd like a puzzle and don't measure, of those 10 different stopping points (or finishes), which would be the one best suited for certification? The shortest, middle, longest or average?

hmm.. My guess is that the average is probably closest to the theoretical "correct" answer, but the longest is probably best suited for certification, since it is the only one that includes all 10 measurements...

To be a stickler for the rules, you'd pick the shortest, and add on whatever distance needed to bring it up to the required minimum. But in practice, I think group rides tend use the average or the mean. I can't recall what we did in Pitt 2000 when we had 7 or 8 guys riding the OT course. I'll check and post.