Timing the Gate

stuckey301
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10
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3/8/2009
Location
EL MIRAGE, AZ, USA

After seeing Sexton’s incredible gate timing at the muddy San Francisco SX, it got me thinking… how random are the gate drops?

“…at least 5 seconds, but not more than10 seconds,” according to the Rule Book.

As a geek, I did some analysis over 100+ gates drop in 14 SX rounds in ‘23 and ‘24. Feel free to look at the data and the analysis.

TL;DR:

It’s pretty predictable; just dump the clutch at 5.42 seconds after the board goes sideways in the your next 450 main.

summary analysis

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enketchum
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4/16/2024 11:46pm

I think we all know who to really ask.... 

WORLD TWO-STROKE FLASHBACK: THE TRUE STORY OF MIKE ALESSI'S $30,000 PAYDAY  - Motocross Action Magazine

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dsmith
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way north, IN, USA
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4/17/2024 5:09am Edited Date/Time 4/17/2024 5:23am

Watch and listen for the sliding shaft..at the pivot point on the starting gate...

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1
4/17/2024 5:12am
dsmith wrote:

Watch and listen for the sliding shaft..at the pivot point on the starting gate...

You're talking about the starting gate?

5
3
dsmith
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4/17/2024 5:22am
dsmith wrote:

Watch and listen for the sliding shaft..at the pivot point on the starting gate...

You're talking about the starting gate?

Well ya

1
1

The Shop

4/17/2024 5:32am
dsmith wrote:

Watch and listen for the sliding shaft..at the pivot point on the starting gate...

You're talking about the starting gate?

dsmith wrote:

Well ya

Better off staring next to the dog box, and start on movement inside the dog box, or if it's a pneumatic system listen for the valve...

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4/17/2024 5:53am

Back in the day I would stare at a paint chip or a weld spot if it just quivered hammer down!

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3
4/17/2024 5:57am

Back in the day I would stare at a paint chip or a weld spot if it just quivered hammer down!

Back in the day, I'd wait for the rubber band to move!

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3strokemx
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4/17/2024 6:00am

image-20240417085212-1Cool idea! 

I disagree with your simplification of 5.2 seconds though, looks to be a bi-modal distribution but I think your analysis assumes a normal distribution?


 

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3strokemx
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4/17/2024 6:03am

Also, what happens when the AMA violates their own rule and drops the gate <5 seconds after the card turn?
Looks like it happens close to 10% of the time.

1
4/17/2024 6:10am
3strokemx wrote:
Also, what happens when the AMA violates their own rule and drops the gate <5 seconds after the card turn? Looks like it happens close to...

Also, what happens when the AMA violates their own rule and drops the gate <5 seconds after the card turn?
Looks like it happens close to 10% of the time.

Human error, a guy looking at a stopwatch activates the gate, would be better to push a button when the card turns, and have a random timer 5-10 seconds later activate the gate.

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1
3strokemx
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4/17/2024 6:51am
3strokemx wrote:
Also, what happens when the AMA violates their own rule and drops the gate <5 seconds after the card turn? Looks like it happens close to...

Also, what happens when the AMA violates their own rule and drops the gate <5 seconds after the card turn?
Looks like it happens close to 10% of the time.

Human error, a guy looking at a stopwatch activates the gate, would be better to push a button when the card turns, and have a random...

Human error, a guy looking at a stopwatch activates the gate, would be better to push a button when the card turns, and have a random timer 5-10 seconds later activate the gate.

They penalize riders for human error, seems like a double standard Smile

1
Tim507
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4/17/2024 7:54am

When I was racing in Germany in the early 70’s, the gates were forward falling mechanical contraptions of all types. One just went and studied the mechanism and then worked hard to qualify first in timed practice on Saturday. Line up where the mechanism was exposed and wait for a bit of motion.

In the late 70’s and early 80’s, there was a track in Yakima called Sun Target and it had a forward falling mechanical gate. One year at the Over the Hill Races over 6 starts (30 expert) I grabbed 5 hole-shots. Missed the 6th one to a friend who at dinner Saturday evening asked me WTF – I shared.

3
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Soul Indigo
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4/17/2024 8:13am Edited Date/Time 4/17/2024 8:15am

We all timed it poorly at the last raceWoohoo

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stuckey301
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EL MIRAGE, AZ, USA
4/17/2024 7:17pm
3strokemx wrote:
Cool idea!  I disagree with your simplification of 5.2 seconds though, looks to be a bi-modal distribution but I think your analysis assumes a normal distribution...

image-20240417085212-1Cool idea! 

I disagree with your simplification of 5.2 seconds though, looks to be a bi-modal distribution but I think your analysis assumes a normal distribution?


 

Great point @3strokemx !

I do check for normalcy in pg 6 with the QQ plot:


If the data were exactly normally distributed, all points would fall on the straight line.  I fudge it and say “close enough,” but it is a bit of a violation of the MLR assumption for the residual error (and by implication the dependent value being regressed ) to be normally distributed.  

Perhaps a log-transformation gives a better fit…I’ll have to check it out.
 

 

2
CDA331
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Coeur D Alene, ID, USA
4/17/2024 8:09pm

Yeah, I always got good Starts at Sacramento Raceway as I would lineup where the doghouse was supposed to be but it was just a rope so as soon as I saw that rope yank, I popped the clutch just a little bit early and always got good starts lol

1
1
4/17/2024 8:39pm

Back in the day I would stare at a paint chip or a weld spot if it just quivered hammer down!

You’re supposed to look beyond the gate and have the gate itself in your peripheral 

1
4/17/2024 9:02pm

Back in the day I would stare at a paint chip or a weld spot if it just quivered hammer down!

You’re supposed to look beyond the gate and have the gate itself in your peripheral 

You're supposed to get the holeshot, by whatever method works for you!

4
msp332
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San Mateo, CA, USA
4/18/2024 10:35am
Human error, a guy looking at a stopwatch activates the gate, would be better to push a button when the card turns, and have a random...

Human error, a guy looking at a stopwatch activates the gate, would be better to push a button when the card turns, and have a random timer 5-10 seconds later activate the gate.

Agree. IMO track which human is doing the gate drop, and group data per person. A truly randomly generated number would be the best way. This could be a mechanical system or a human using a random-number generator program. I can't recall ever seeing a gate drop after 9s.

I would be more interested in ability to predict timing on the gate drop for the main based on earlier gate drops that day. I have no data, but when I count from the stands it seems like basing it on the last few starts is most likely to be a repeat.

Flatliner
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CA
4/18/2024 1:38pm

The 9-10 second mark feels real long both when you're watching, or racing.

1
spimx
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4/18/2024 1:58pm

The sooner the better before my heart jumps out of my chest......

Anyone here feel that? 

1
Gator 4
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Southern California, CA, USA
4/18/2024 7:26pm

I am surprised there are not more guys rolling before the start.  If you are not a top 10 guy, why not.  There is a bit of room for the bikes to be backed up a little.  If you are rolling, even the slightest bit, you will smoke the guys that are completely still.

1
ando
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Perth, AU
4/18/2024 10:17pm
stuckey301 wrote:
After seeing Sexton’s incredible gate timing at the muddy San Francisco SX, it got me thinking… how random are the gate drops? “…at least...

After seeing Sexton’s incredible gate timing at the muddy San Francisco SX, it got me thinking… how random are the gate drops?

“…at least 5 seconds, but not more than10 seconds,” according to the Rule Book.

As a geek, I did some analysis over 100+ gates drop in 14 SX rounds in ‘23 and ‘24. Feel free to look at the data and the analysis.

TL;DR:

It’s pretty predictable; just dump the clutch at 5.42 seconds after the board goes sideways in the your next 450 main.

summary analysis

Your linear model appears to predict the most likely gate drop time from the dataset.  Looking at your histogram though it's clearly bimodal at around 5.25 and 5.75 secs (not sure what your bin size was).

The problem is that predicting the drop has a binary outcome - you go sometime after the gate (success) or you go some time before gate (fail).  The way the histogram looks that would have about a 50% success rate - no one is going risk that on an ongoing basis.  

Perhaps on a case by case basis like SF where the difference between being out front and not was so great it was worth the risk.

WhipMeister
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Big D, TX, USA
4/18/2024 10:34pm

I only know what's worked for me. And I'm not telling.Tongue​​​​​​

But I'm really enjoying the Statistics lesson.

aees
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Location
USA
4/19/2024 2:52am
stuckey301 wrote:
After seeing Sexton’s incredible gate timing at the muddy San Francisco SX, it got me thinking… how random are the gate drops? “…at least...

After seeing Sexton’s incredible gate timing at the muddy San Francisco SX, it got me thinking… how random are the gate drops?

“…at least 5 seconds, but not more than10 seconds,” according to the Rule Book.

As a geek, I did some analysis over 100+ gates drop in 14 SX rounds in ‘23 and ‘24. Feel free to look at the data and the analysis.

TL;DR:

It’s pretty predictable; just dump the clutch at 5.42 seconds after the board goes sideways in the your next 450 main.

summary analysis

ando wrote:
Your linear model appears to predict the most likely gate drop time from the dataset.  Looking at your histogram though it's clearly bimodal at around 5.25...

Your linear model appears to predict the most likely gate drop time from the dataset.  Looking at your histogram though it's clearly bimodal at around 5.25 and 5.75 secs (not sure what your bin size was).

The problem is that predicting the drop has a binary outcome - you go sometime after the gate (success) or you go some time before gate (fail).  The way the histogram looks that would have about a 50% success rate - no one is going risk that on an ongoing basis.  

Perhaps on a case by case basis like SF where the difference between being out front and not was so great it was worth the risk.

It doesnt have to be a fail. If you "go smoothly", you can still pull in the clutch if you notice it ain't there.

They should expand to be between 5-7sec for something like 75-85% of the time, with occasional 8-9sec. The 10 I think you can just drop.

Soul Indigo
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Phuket, TH
4/19/2024 3:18am
enketchum wrote:
I think we all know who to really ask.... 

I think we all know who to really ask.... 

WORLD TWO-STROKE FLASHBACK: THE TRUE STORY OF MIKE ALESSI'S $30,000 PAYDAY  - Motocross Action Magazine

Johnny Moore? 

2
zippytech
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Location
Bethesda, OH, USA
4/19/2024 9:57am

You guys talking about listen to the gate are funny, I am sure you can hear a pin drop with 40 bikes pinned after the card turns sideways.

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