Drummond Chart Now Up

[gh]

Go to the front page and you'll see (under the title "Did Drummond Get Robbed?") the official pressure-plate readouts from the infamous Paris quarterfinal. Draw your own conclusions.

As noted in the posting here, there's more analysis in the magazine itself. You can't have everything for free!

ps--if you think you saw the charts posted for about 90 seconds yesterday, you did, but that was the pre-verbiage test window that inadavertently got posted prematurely.

[tafnut]

Re: Drummond Chart Now Up

I don't think there's much interpreting to do - he did not false start in the truest sense of that term. The question remains - do we need 'better' technology, or just a human who will make the right call?

[JRM]

Re: Drummond Chart Now Up

Talk about jittery! Drummond's foot is clearly wiggling more than anyone elses. In fact, he potentially could have triggered the signal *before* the gun. Note the sinusoidal (wave) shape of his pressure-plate signal, as compared to the other lanes. Everyone else is *very* still. In a sense, that evidence alone could favor a false start.

Playing devil's advocate, one could almost say that he was "revving" up to a start, which one could construe as a type of rolling start. Again, though, this is all happening within 5 hundrethds of a second, which makes it an unconscious activity.

In any event, while Drummond obviously didn't break until after 0.1s, he certainly shows unusual movement in the blocks well before the gun fires.

The other option is a faulty pad sensor, which that data might also suggest (i.e. why his signal is so unsteady, as compared to others). Perhaps the blocks could have been impounded for testing, and he should have asked for a new set (under the protest).

[bhall]

Re: Drummond Chart Now Up

One thing I think anyone who saw the original call and replays will say is that Drummond did not "move." His hips, legs, and torso were rock steady.

Also note that the foot twitch lasts less than .05 seconds. Without the sensing blocks in place no starter on this planet would have called him for a false start.

[JRM]

Re: Drummond Chart Now Up

>Also note that the foot twitch lasts less
>than .05 seconds. Without the sensing blocks in
>place no starter on this planet would have
>called him for a false start.

I will qualify my response by saying that I would probably chalk this up to mechanical error. To me it looks like the sensor readings are irratic compared to the rest of the field. There's some kind of oscillatory reading coming from his blocks, which suggests that the sensors needed
"tightening".

I gave the other options as "devil's advocate" offerings.

[bhall]

Re: Drummond Chart Now Up

You may be right about the sensor. I wonder if the blocks have some kind of signature that could be used to compare the reading they produces across races and days?

[Guest]

Re: Drummond Chart Now Up

Thanks for the graphs. Also impressed with the above analysis. I'm curious to know what the units and scale of the vertical axis is. Obviously pressure, but how much?

[bhall]

Re: Drummond Chart Now Up

Units are in kilograms, which I find odd. I'd think that the measure would be one of pressure (Pascal). Baseline on the graph is 0 kg, top line is 125 kg. So each segment is 25 kg.

[BlueCurve]

Re: Drummond Chart Now Up

Nice analysis JRM. But before we let the poor workman blame his tools, can we have a closer look.

Why is everyone concentrating on the leading edge of the pressure graph ?

If you look at the trailing edge, Powell is completely off the blocks (zero pressure) first, followed very closely by Drummond.

Looks to me like he got an advantage.

But I'd like to qualify this. I can't figure why we see only one pressure graph ? What's happening with the other foot ? Is it allowed to do whatever ?

[Guest]

Re: Drummond Chart Now Up

But I'd like to qualify
>this. I can't figure why we see only one pressure
>graph ? What's happening with the other foot ? Is
>it allowed to do whatever ?


That's something that had just come to me as I was further thinking about this. I'm not a sprinter, so perhaps one of the speed types could explain the starting action, but wouldn't there be rather different curves for each block?

I would guess that the forward foot would be exerting most of the pressure backwards to drive the body (and the trailing leg) forward, while the trailing foot would only have minimal pressure backwards and more of a negative pressure change as it pulls forward to get into the first stride out of the blocks.

Furthermore, what motion explains the second, lower, 'hump' in all the pressure graphs? Would that be the result of a final ankle 'flick' as the leg as fully extended?

[Guest]

Re: Drummond Chart Now Up

For what it's worth, LOTS of sprinters in Paris were complaining that those particular blocks were too sensitive. Said Kim Collins: "You can't as much as pass gas without a false start."

[Guest]

Re: Drummond Chart Now Up

>Why is everyone concentrating on the
>leading edge of the pressure graph ?

If you look at the trailing edge, Powell is completely
off the blocks (zero pressure) first, followed
very closely by Drummond.

Looks to me like he
got an advantage.>>

Only logical that Powell would be off the blocks first, since he's the first (by quite a bit) to initiate the starting motion.

As for Drummond being next, isn't that explained by his renown as a good starter? He has great "quicks" out of the blocks, so I'd expect him to be at the forefront of the trialing-edge people. No?

[Guest]

Re: Drummond Chart Now Up

I would have expected Louise T to have weighted in on this topic by now, since she was so nonstop about it when the situatin first happened. Maybe she does not want to tlak about the fact that a look at all those charts, while it tends to prove Jon's innocence, also puts the lie to all those claims about 0.100 being a bad guide for tolerance. It seems pretty obvious to me that Drummond and everybody else pretty much falls into that "0.14" range I don't see any supermen out there

[Guest]

Re: Drummond Chart Now Up

>I would have expected Louise T to have weighted
>in on this topic by now, since she was so nonstop
>about it when the situatin first happened. Maybe
>she does not want to tlak about the fact that a
>look at all those charts, while it tends to prove
>Jon's innocence, also puts the lie to all those
>claims about 0.100 being a bad guide for
>tolerance. It seems pretty obvious to me that
>Drummond and everybody else pretty much falls
>into that "0.14" range I don't see any supermen
>out there

here i am...from the hilton in athens and the ioc olympic world congress on sport sciences...checking the scientific evidence for the 0.100...see other post......