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re: What would Usain Bolt's 40 yard dash time be?

Posted on 8/5/12 at 9:10 pm to
Posted by SaintCajun
Pacific Northwest
Member since Apr 2012
4294 posts
Posted on 8/5/12 at 9:10 pm to
quote:

You can't do it that way. His speed wasn't constant. It was still increasing when he hit the 36.5 meter mark.


So you're saying people run the 40 yard sprint at a constant speed? 40 meters = 43.7445319 yards, which means his speed at 40 meters is equivalent to the speed he would reach at 40 yards
Posted by bobbyray21
Member since Sep 2009
9490 posts
Posted on 8/5/12 at 9:47 pm to
quote:

So you're saying people run the 40 yard sprint at a constant speed? 40 meters = 43.7445319 yards, which means his speed at 40 meters is equivalent to the speed he would reach at 40 yards



That wasn't even close to what I was saying.
Posted by bobbyray21
Member since Sep 2009
9490 posts
Posted on 8/5/12 at 10:11 pm to
Here are the splits when Bolt ran a 9.58





RT: 0.14

0-10: 1.89
10-20: 0.99
20-30: 0.90 (3.78 @ 30m)
30-40: 0.86 (4.64 @ 40m)
40-50: 0.83

40 yards == 36.576 meters.

Bolt was at 3.78 at 30 meters and he ran the next 10 meters in 0.86. As you can see, he is still accelerating at that point, so multiplying 0.86 * 0.576 would be a slight underestimate of his 40 time. But as you can see, his rate of acceleration has drastically slowed down at that point. There is a way to figure out the exact time he took to travel that .576 meters, but I don't know how to do it, and I do know that since his next split was .83, simply dropping the 0.86 down to a .85 makes for a very close approximation. So that's what we're gonna do.

3.78 + (0.85 * 0.576) == 4.27 seconds.

BUT BUT BUT, in the olympics the clock starts the gun, and at the combine the clock starts when the runner starts.

This is where the reaction time comes into play.

4.27 - 0.14 == 4.13 seconds. Damn...that's fast.

(1) BUT BUT BUT, sprinters get a starting block, which helps lessen the effect of the reaction time because they can come off the block more quickly.

AND

(2) BUT BUT BUT, sprinters are running on a track, not on turf.

AND

(3) BUT BUT BUT, you looked at the data for Bolt's Best. Race. Ever. He doesn't run that fast every time.

So start with the time of 4.13 and adjust upwards based on the three BUT BUT BUT factors. The third factor is discretionary. You can always just run the numbers from whatever race you wish. All of them will be slower than the above numbers since it was by far his best race ever.

To deal with BUT BUT BUT factors #1 and #2....well I don't know what you do. How much time is the track worth versus the turf? How much time are starting blocks worth? I don't know the answers to those questions. Perhaps somebody else does.

Either way, in view of all of the above, if Bolt shows up at the combine with only 3 opportunities to post a time in the 40 yd dash, I would bet against him posting a sub 4.2 time. Could he conceivably do it? Sure...see above. But, again, that is all best case scenario and doesn't account for some potentially slowing factors.

My Ultimate Conclusion #1:
I think Chris Jonson vs. Usain Bolt in a 40 yd dash would be a tight race.

My Ultimate Conclusion #2:
A sub 4.10 40 yd dash has been run twice in history. Once by the Easter Bunny. The other time by Santa Claus.



Posted by LSUtigersarefun
Member since Aug 2009
9602 posts
Posted on 8/5/12 at 10:18 pm to

here is what I worked off of.
Posted by Tiger1242
Member since Jul 2011
31854 posts
Posted on 8/5/12 at 10:21 pm to
Shut the god damn thread down bobbyray ended that shite
Posted by bobbyray21
Member since Sep 2009
9490 posts
Posted on 8/5/12 at 10:28 pm to
quote:

here is what I worked off of.


Nifty. Our numbers ended up coming out reasonably close.

I read a comment in pro football reference article where this discussion came up. Some dude actually ran a best fit analysis and the numbers indicated that it would be no lower than 4.11 and no higher than 4.14.

So I like the 4.13 number....again, as a base number before we take into account the BUT BUT BUT factors.
Posted by bobbyray21
Member since Sep 2009
9490 posts
Posted on 8/5/12 at 10:28 pm to
quote:

Shut the god damn thread down bobbyray ended that shite


Posted by bobbyray21
Member since Sep 2009
9490 posts
Posted on 8/5/12 at 10:46 pm to
Aside: I think it would be really awesome to be the fastest man in the world.
Posted by Interception
Member since Nov 2008
11089 posts
Posted on 8/6/12 at 7:00 am to
quote:

That equation assumes uniform speed throughout. The better measure would be to take his 20m split and add that to ratio like you have shown. Still not perfect but much better. My guess is he was in the upper 4.18 range.

ETA: frick it. I ran the numbers:

Using the chart on page 3
40 yard = 36.576 meters = 30 meters + 6.576 meters
6.576 m = 7.19 yds

40 yard time = 30 meter time + 7.19 yard time
30 meter time = (0 to 30 m splits - reaction time) = 3.615s
7.19 yard time = average of 30 m and 40 m time divided by 10.94 yds multiplied by 7.19 yds = (.89s/10.94)x7.19 = .585s
3.615s + .585s = 4.200

someone can check my math and my assumption if they want


The math is right. Ill have to take up your assumption later but at first glance this looks more in line with my thinking that the other formula.
Posted by Interception
Member since Nov 2008
11089 posts
Posted on 8/6/12 at 7:14 am to
quote:

Either way, in view of all of the above, if Bolt shows up at the combine with only 3 opportunities to post a time in the 40 yd dash, I would bet against him posting a sub 4.2 time. Could he conceivably do it? Sure...see above. But, again, that is all best case scenario and doesn't account for some potentially slowing factors.


I absolutely agree with you on this. We are talking about ideal surface, spikes and conditions in London/ Beijing. The combine is a controlled environment but we generally see higher times at the combine than times coming out of the schools (if you know what I mean).

Only factor that I see that would work in Bolts favor is that that the clock works off his reaction time instead of the gun, but there are no starting blocks at the combine. The basic advantage/ disadvantage cancel each other out. Bolt would not run sub 4.2 at the NFL combine as we see it now IMO. Also the 40 yard dash is a very short race so yea it would be damn tight with a Chris Johnson or Trindon Holiday.
This post was edited on 8/6/12 at 7:16 am
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