Your reading comprehension is not good. He clearly wrote "from venue to venue or from day to day" NOT for runners in the same race.
What? It's a timer. Swimming timers can capture to the thousandth from venue to venue and from day to day
Swimming is different. The time is based on when the swimmer touches the wall. The time in track is based on a human interpretation of when the torso crossed the finish line.
Also, in track there are a number of factors that contribute to the final time. Yes, the clock itself is accurate beyond the 1/100th second, but the other factors (camera position, ZGT, human interpretation, etc.) mean that we can not be certain of a time beyond the 100th.
"different tracks using different timing systems, different finish line cameras, different ZGT calibrations etc,"
This is the case whether you are measuring to 1/100th or 1/1,000 of a second.
If you calculate the potential error due to track length it is about .001 sec. Similarly the error due to the ZGT can be up to 0.001 sec. Camera position can add another 0.001 of uncertainty. When you add all these together and add in other uncertainties you have several 1/000ths of a second uncertainty. However, you do not get close to 1/100ths uncertainty. Therefore when comparing performances set under different conditions you can feel confident you are performing an accurate comparison to 1/00th of a second but not if you go to 1/000ths of a second.
What? It's a timer. Swimming timers can capture to the thousandth from venue to venue and from day to day
Swimming is different. The time is based on when the swimmer touches the wall. The time in track is based on a human interpretation of when the torso crossed the finish line.
Also, in track there are a number of factors that contribute to the final time. Yes, the clock itself is accurate beyond the 1/100th second, but the other factors (camera position, ZGT, human interpretation, etc.) mean that we can not be certain of a time beyond the 100th.
But we can be more certain than the hundredths.
You have all got to be kidding me. Hot rods go upward of 300 mph, for a few seconds and the timer can gauge a close race to the thousandth.
If they can trust it at 300 mph, how can we have THAT much uncertainty at about 12 TIMES slower per hour ?
I agree that if a 9.572 is faster than a 9.579, the 9.572 should be the only WR.
You are constantly obsessing with the time but in reality the measurement is a compound measurement. The following factors all play into the measurement:
The measurement accuracy of the timing device
The length of the course (See WA Facilities Manual for the allowed tolerances)
The location of the finish line camera
The assessment of when the torso broke the line.
Zero Gun Test delay (See WA Rules for allowable delay)
I know, its a millisecond here, a millisecond there but they all start to add up. Ultimately you can have no confidence that a the runner who records 9.572 is actually faster than a runner who recorded 9..579.
This is the best answer here, that there are stackups in tolerances such that we don't confidence in results down to the 0.001 second between facilities. But, within a particular race, the position of the finish line is equal so you can mostly read the photo finish photo down to the 0.001second.
Let's put some numbers to how the length of the track can differ between facilities.
There’s a lot of people who think the BU track is not 200m in length. These people would be correct.
We want to share the truth.
And that truth is…the track at Boston University is LONG
1.4cm each lap to be exact, we apologize for making everyone run that little bit extra 😂 pic.twitter.com/kWPkTxY9ue
So on a 200m track, the maximum amount a track can be long is 4cm. That means a 400m track can be 8cm long and be certified as 400m. So certified 400m tracks range from 400.00 meters to 400.08 meters.
Look at a photo finish photo. Each tick mark is 0.01 second. Can you really tell with confidence 1/10th of the tick marks? Sometimes yes, sometimes no, depending on how well you can see the torso and how sharp the photo is. I mean, though assured in another thread that it looks right from the opposite side camera, it looks like they put the line here on the bicep, which would be giving a 0.003 second benefit of the doubt. Any fuzziness of the photo can be +/- at least 0.001 second. Judging where the torso is over a singlet/shirt can be +/-0.001 second depending on body position.
That's why for timing, there is a limit to how precise you can measure and be confident that the performance on one track is actually better than the performance on another track. And that limit was chosen to be 0.01 second for track. Add up the tolerances and you just don't have the confidence that 9.572 second on one track and one photo finish photo is the same as 9.572 second on another slightly different but still certified track and photo finish photo.
Homest Mike and Great Dane obviously didn't learn the difference between accuracy and precision in school or work in a field where that is important. You two are arguing to apply false precision to track:
wiki author wrote:
False precision (also called overprecision, fake precision, misplaced precision and spurious precision) occurs when numerical data are presented in a manner that implies better precision than is justified; since precision is a limit to accuracy (in the ISO definition of accuracy), this often leads to overconfidence in the accuracy, named precision bias.
False precision (also called overprecision, fake precision, misplaced precision and spurious precision) occurs when numerical data are presented in a manner that implies better precision than is justified; since precision is...
Swimming is different. The time is based on when the swimmer touches the wall. The time in track is based on a human interpretation of when the torso crossed the finish line.
Also, in track there are a number of factors that contribute to the final time. Yes, the clock itself is accurate beyond the 1/100th second, but the other factors (camera position, ZGT, human interpretation, etc.) mean that we can not be certain of a time beyond the 100th.
But we can be more certain than the hundredths.
You have all got to be kidding me. Hot rods go upward of 300 mph, for a few seconds and the timer can gauge a close race to the thousandth.
If they can trust it at 300 mph, how can we have THAT much uncertainty at about 12 TIMES slower per hour ?
Hot rod timing is also different than athletics timing. In hot rod racing, the clock starts when the vehicle breaks the laser beam at the starting line and stops when the vehicle breaks the finish line beam. Because the start and stop are physical events that do not require human interpretation it is possible to report times that are accurate to the 1/1000th. This is not the case in athletics. If athletics was time based on when any part of the body broke a light beam at the finish line, it would be possible to report times that are accurate to the 1/1000th.
"different tracks using different timing systems, different finish line cameras, different ZGT calibrations etc,"
This is the case whether you are measuring to 1/100th or 1/1,000 of a second.
If you calculate the potential error due to track length it is about .001 sec. Similarly the error due to the ZGT can be up to 0.001 sec. Camera position can add another 0.001 of uncertainty.
I have watched races in which I and the announcer disagreed with the official order of finish after seeing the photo. I recall Flotrack spending time disputing a high level race.
Some posters don’t seem to understand the difference between precision and accuracy. FAT timing can measure and report more decimal places than is accurate, i.e., if you could hypothetically have the runners run the exact same race with the exact same times — hypothetical because only some divine oracle type would be able to know the times are exactly the same — FAT timing is not guaranteed to give you the same thousandth place (which by consequence technically is true even for the hundredth place, but is just much less likely).
This source of inaccuracy is independent of the tolerances of track distances that is 0.01% or 1cm for 100m, which translated to time would be ~0.001s, so millisecond times won’t be accurately comparable across tracks.
You are constantly obsessing with the time but in reality the measurement is a compound measurement. The following factors all play into the measurement:
The measurement accuracy of the timing device
The length of the course (See WA Facilities Manual for the allowed tolerances)
The location of the finish line camera
The assessment of when the torso broke the line.
Zero Gun Test delay (See WA Rules for allowable delay)
I know, its a millisecond here, a millisecond there but they all start to add up. Ultimately you can have no confidence that a the runner who records 9.572 is actually faster than a runner who recorded 9..579.
This is the best answer here, that there are stackups in tolerances such that we don't confidence in results down to the 0.001 second between facilities. But, within a particular race, the position of the finish line is equal so you can mostly read the photo finish photo down to the 0.001second.
Let's put some numbers to how the length of the track can differ between facilities.
So on a 200m track, the maximum amount a track can be long is 4cm. That means a 400m track can be 8cm long and be certified as 400m. So certified 400m tracks range from 400.00 meters to 400.08 meters.
Look at a photo finish photo. Each tick mark is 0.01 second. Can you really tell with confidence 1/10th of the tick marks? Sometimes yes, sometimes no, depending on how well you can see the torso and how sharp the photo is. I mean, though assured in another thread that it looks right from the opposite side camera, it looks like they put the line here on the bicep, which would be giving a 0.003 second benefit of the doubt. Any fuzziness of the photo can be +/- at least 0.001 second. Judging where the torso is over a singlet/shirt can be +/-0.001 second depending on body position.
That's why for timing, there is a limit to how precise you can measure and be confident that the performance on one track is actually better than the performance on another track. And that limit was chosen to be 0.01 second for track. Add up the tolerances and you just don't have the confidence that 9.572 second on one track and one photo finish photo is the same as 9.572 second on another slightly different but still certified track and photo finish photo.
Homest Mike and Great Dane obviously didn't learn the difference between accuracy and precision in school or work in a field where that is important. You two are arguing to apply false precision to track:
wiki author wrote:
False precision (also called overprecision, fake precision, misplaced precision and spurious precision) occurs when numerical data are presented in a manner that implies better precision than is justified; since precision is a limit to accuracy (in the ISO definition of accuracy), this often leads to overconfidence in the accuracy, named precision bias.
Within your definition given (and again personal slighting of both me and great Dane which you're not really entitled to and are taking great latitude in doing so in a discussion of this SUBJECT...not people)...it says "implies better precision than is justified." Now, since you want to go at it in this manner, I'm going to be very direct with you: If some of us believe that 9.572 should be ratified as 9.572 then that's our prerogative as people who know the sport, just like others here know the sport.
Since you must use insults to drive your point, I can assure you that your status within the sport is not large enough to insult either of us and it certainly is not going to sway our opinion of what we think is right and just.
World Athletics made their choice, but we have every right to question it and we do not owe you even a half cent or any regard to do that.
You have not shown you know anymore... you're simply using your ideas to justify hundredths over thousandths just like we are doing the opposite.
If you calculate the potential error due to track length it is about .001 sec. Similarly the error due to the ZGT can be up to 0.001 sec. Camera position can add another 0.001 of uncertainty.
Where did you obtain these #s?
World Athletics Facilities Manual and Technical Rules gives the permitted tolerances on track length and the maximum error on the ZGT.
For example Facilities Manual Section 2.2.1.6 states: The deviation from the running length of all start lines must not exceed +0.0001 x L where L is the length of the race. This implies that in a 100 metre race lane 7 can be up to 1 centimeter longer than lane 1 and the track is still legal. One centimeter takes about .001 seconds to cover for Olympic Class athletes.
Similarly Section 2.1.3.1 specifies that a track can have a downward gradient of up to 0.1%.. So for the 100 metres the finish line can be 10 centimeters lower than the start line. I haven't done a calculation to see what this equates to but it is obviously a variable.
Technical Rules 19.13.2 The System shall be started automatically by the Starter's signal, so that the overall delay between the report from the muzzle or its equivalent visual indication and the start of the timing system is constant and equal to or less than 0.001 second. (Note also that the the trigger can be either acoustic or visual, another variable)
Basically measurement uncertainty is something of a rabbit hole. The deeper you dig the more uncertainty you uncover. In the end all you can do is draw a line in the sand and state that to this level of accuracy we have a high degree of confidence we can make accurate comparisons. Beyond that level - we are into a grey zone.
