100m WR measured to 1/1000 sec

[gamble]

I'm interested in finding out the last dozen or so 100m WR measured to 1/1000 sec. I have Bailey at 9.835 and would like to know some of the others (inc. Tim's 9.78 and Ben's 9.83 & 9.79).

Thank you.

[gh]

One would hope that few people have been silly enough to take such readings, meaningless as they are except in a tie-breaking sense in any given race.

[Marlow]

One would hope that few people have been silly enough to take such readings, meaningless as they are except in a tie-breaking sense in any given race.

amen (though I could have sworn you were agin me in my railings about the meaningless of thousandths of a second timing).

[rasb]

Same reaction after technology supported 1/100th timing, I presume.

[26mi235]

Same reaction after technology supported 1/100th timing, I presume.

No, the errors are in a range (length of the track, etc), where marks in different locations and at different times, cannot be determined within the noise. However, the difference between 9.80 and 9.90 is much bigger, and all you have to do is to look at who occupies the lists within the better than 9.80 vs 9.90 and 9.90 vs 10.00 etc to see that there really is a difference at the level of 0.1 seconds.

[trackworld]

Tim Montgomery's 9.78 was 9.772

Gatlin's 9.77 was 9.766

[ppalmer]

Same reaction after technology supported 1/100th timing, I presume.

To add to 26mi235's comments.

Sound travels about 1000 feet/second. So to produce a fair start for all runners, one would need to equalize their distance from the start signal to about 1 foot accuracy.

At the .001 level, that means locating the runner to about 1cm. It is not hard to do that when they are in the same photo -- if it is an adequate photo. But, to make sure that the runners were read in a consistent way to that accuracy is not so easy. The way we usually do it is make sure the same person reads all of the heats of a given event (which is when .001 accuracy is used to break ties).

Comparing meets raises other issues. If you send your FinishLynx back once a year for calibration, it is supposed to be good to .001 sec. Presumably other systems are similar. (I don't know how many people send the systems back for re-calibration -- I don't know any.) However, there are still "local" questions: what is the delay between when your gun was is fired and when the clock starts to .001 accuracy? Different pickups would be used and may differ. One would need to worry about all of the interconnections. Although electrical signals travel fast enough not to cause worries at the .001 sec level, the responses of the electronics being interconnected are not anywhere near as fast.

More generally, every time you try to improve a clock by a factor of 10, you will learn new things -- and usually not without pain.

Pat Palmer

[Marlow]

Perhaps someone with some photo-reading experience can enlighten me, but when I see a meet with a scoreboard, and the results start coming up very quickly after the finish (the Fla Relays pops to mind, where all 8 placers are up there within 15-20 seconds after the race), how can we believe that any care whatsoever was given to placing the cursor on the right spot of the torso? I ducked my head in the timing tent one time and what I saw was a guy with a mouse who would place it on the chest in less than a second and click the mouse. I saw that there was no fine-tuning going on, just point and click, point and click, point and click, eight times in about 10 seconds. How is that accurate? The image, by the way, was about 8x10.

[ppalmer]

Perhaps someone with some photo-reading experience can enlighten me, but when I see a meet with a scoreboard, and the results start coming up very quickly after the finish (the Fla Relays pops to mind, where all 8 placers are up there within 15-20 seconds after the race), how can we believe that any care whatsoever was given to placing the cursor on the right spot of the torso? I ducked my head in the timing tent one time and what I saw was a guy with a mouse who would place it on the chest in less than a second and click the mouse. I saw that there was no fine-tuning going on, just point and click, point and click, point and click, eight times in about 10 seconds. How is that accurate? The image, by the way, was about 8x10.

Some people read an unholy number of photos and get very fast (I am not very fast). The relevant thing for the photo, at 500 lines/second rate -- a relatively slow rate -- 20 pixels will be in the same .01 second. So the cursor does not have to placed extremely precisely. (The screen is showing as you move the cursor the "boundary" is between subsequent .01 seconds.)

It also depends very much on the result -- how close together the runners are, how much people are blocked by random arms and legs, etc. Most are pretty easy and fast to read, but every once in a while one comes up that takes a while.

Pat Palmer

(added May 13, 08):
I notice that my arithmetic is screwed up. At 500 lines/sec, lines are .002 apart, so only 5 in the same .01 sec. Normally when reading sprints rates like 800 or more lines per second are used. (Note this is the number of lines. While the number of screen pixels is much higher, they are not labeled by the program.) However, the conclusions are not changed.

[gh]

I've seen FlashResults guru Roger Jennings have the winner of a 100 on the board before the last guy is across the line.

[Marlow]

The relevant thing for the photo, at 500 lines/second rate -- a relatively slow rate -- 20 pixels will be in the same .01 second. So the cursor does not have to placed extremely precisely. (The screen is showing as you move the cursor the "boundary" is between subsequent .01 seconds.)Pat Palmer

Thanks, Pat (cool name, by the way). That does answer my questions and gives me more confidence in the quick-fingered guys.

[George P.]

Not sure why ... but this thread made me think of a washingtonpost.com sports article I read this morning. It concerns a local lady who is in a family way (as we used to say) but who continues to be quite a successful road racer. She relates an incident where she was barely nicked by another runner:

"If I had put the [timing] transponder on my belly, I would have had her," Gruendel said.

http://www.washingtonpost.com/wp-dyn/co ... 02164.html

Added -- Happy Mothers' Day

[fez]

Hi everyone. I've been meaning to throw this idea into the mix for a while on the 100m threads I've seen. It never gets mentioned and this seems like a suitable 100m thread so hear goes:

A while ago I read an article on the internet about the introduction of "direct sound" to the start of races and it's affect on 100m times. I can no longer find the article unfortunately.

I might have my terminology wrong but from what I remember "direct sound" is when the starters pistol is linked to speakers situated behind the athletes at the start line so that they all hear the gun at exactly the same time. The perceived problem being the time delay from the gun going off on the infield to the athletes on the track hearing it and the disadvantage that this puts on the athletes in the outer lanes. "Direct sound" was shown to level out the reaction times from lanes 1-8 and to improve reaction times by anything between 0.05 and 0.1 seconds on average.

"Direct sound" was officially introduced around 1995 and used in that years World Championships and every edition of WCs since. However it was not used at the Sidney Olympics and one of the conclusions in the article was that this may have robbed Maurice Greene of a chance to break the 100m world record in the final.

Now I've probably got the figures slightly wrong but from what I remember it was fair to conclude that any 100m time from post 1995 (except in Sidney and possibly Atlanta) was worth at least 0.05 less compared to a time run pre-95, before the introduction of direct sound.

Hope this makes sense. Stop me if I'm talking utter rubbish because its very possible that I've got my dates and figures mixed up. However I feel it's an important point just as people discuss wind readings and altitude to try and find meaningful comparisons between historical performances.

(Apologies also if this has already been brought to your attention and I've simply failed to to my forum search properly)

[tandfman]

There was a thread that dealt with this a few years ago.

http://mb.trackandfieldnews.com/discuss ... torder=asc

[fez]

Cool thanks. Perhaps it was the "silent gun" that was introduced in 1995. Can someone confirm this? It still bugs me slightly that this isn't mentioned when comparing 100m times since a "loud gun" can slow the reaction times by a tenth according to some of the data on that old thread.