Anyone seen DAX?

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Marshall Grice
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Anyone seen DAX?

Post by Marshall Grice »

Something kind of new and somewhat interesting.

https://docs.google.com/spreadsheet/pub ... utput=html" onclick="window.open(this.href);return false;

Data-derived Autocross indeX (DAX):
An algorithmic approach to autocross class indexing.


Data In ----(beep)---(boop)---> Index Out

This is several years and hundreds of hours in the making. (I like a challenge ) Version 1.0 is finally finished. Please check it out and let me know what you think.

This also includes a Driver Performance Index (DPI) that "ranks" all national drivers. It is a tool for the algorithm, but is interesting to inspect too. Not a perfect ranking as the competition data is not nearly ideal. But, mostly it does a pretty good job.
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Jeff Stuart
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Re: Anyone seen DAX?

Post by Jeff Stuart »

SHOCKED to see that every single ST index is too high. :roll:
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Re: Anyone seen DAX?

Post by Jeff Stuart »

But in all seriousness, something like this makes a lot more sense to me than relying completely on one guy. (Of course, this was also written by one guy, but it's driven by data rather than unknown magic)

In the thread discussing this on sccaforums (http://www.sccaforums.com/forums/aft/444834" onclick="window.open(this.href);return false;) there are people pointing out that by only considering data from national events on good, rubbered in courses, these numbers wouldn't necessarily be fair when used for regional events at sites that probably have less grip on average, which I think is a valid point.

The Driver Power Index (DPI) tab is pretty interesting. From what the guy says, it seems to be something similar to a ladder algorithm that ranks drivers based on who they beat. He said that drivers who run in classes with many competitors are more likely to be ranked correctly than people who run in smaller classes.
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Craig Naylor
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Re: Anyone seen DAX?

Post by Craig Naylor »

I'm curious how one makes his "Driver team?" For example I noticed I'm not on it... I admit I'm Nationals Trophy fodder, not likely a winner, but I have multiple Nat. level entries, a win, and multiple Nat. event trophies in his 2 year span of data. Lily Liu is included, I think she has a single event in the time span (she ran in STS open), and no trophy.

My point isn't Lilys in and I'm out... but what criteria is he using to be included? Using us as examples in the same class, doesn't make sense.

Everyone complains about Rick's "magic"... Statistics can be made to tell just about any story you want. Just control the data being used. Using us again as the example... I think "Magic" is in use here too, else wise Lily's inclusion, and my exclusion does not make sense.
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Jeff Stuart
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Re: Anyone seen DAX?

Post by Jeff Stuart »

He pulled data from 2012 and 2013, and only National Championships and National Tour data.

You won STS at the 2013 SD Tour, so I agree I would've expected to see you in the listing. Lily was at the 2012 SD Tour, so that's how she got in there, perhaps the 2013 SD Tour was left out?

Are there any other of those ^ events that you were at?
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Bill Martin
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Re: Anyone seen DAX?

Post by Bill Martin »

Many years ago when I could still drive, I had won nationals something like four times in five years...plus one second. I couldn't figure out why my Lotus couldn't even pax in the top half locally.

I got a chance to ask Rick and he said he thought the index should be higher. So he made it higher.

In case you thought he had an algorithm or something.
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Re: Anyone seen DAX?

Post by Ed Holley »

Bill Martin wrote:Many years ago when I could still drive, I had won nationals something like four times in five years...plus one second. I couldn't figure out why my Lotus couldn't even pax in the top half locally.

I got a chance to ask Rick and he said he thought the index should be higher. So he made it higher.

In case you thought he had an algorithm or something.
JEESH!!! So, what are you REALLY trying to say Bill? See, this is the problem with Holy Grails and Sacred Cows. I would hope that what you have said is not true, not doubting you. Because, if it IS true, it certainly makes Rick's analytical conclusions be quite suspect, and makes one wonder if there isn't a better way...DAX or otherwise.
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Rick Brown
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Re: Anyone seen DAX?

Post by Rick Brown »

Wait, this isn't about Star Trek/DS9?
Since light is faster than sound...many people look bright until they speak...
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Bill Martin
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Re: Anyone seen DAX?

Post by Bill Martin »

Ed Holley wrote:JEESH!!! So, what are you REALLY trying to say Bill? See, this is the problem with Holy Grails and Sacred Cows. I would hope that what you have said is not true, not doubting you. Because, if it IS true, it certainly makes Rick's analytical conclusions be quite suspect, and makes one wonder if there isn't a better way...DAX or otherwise.
There was no hidden message. It is what it is. Developing a fault-free index system that will work anywhere with anyone is probably impossible, so you do what you can. I think Rick has tried really hard and a lot of people have gotten a lot of use of his efforts. If he occasionally put his thumb on the scale it was because he thought it the right thing to do. His product, his call.
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Re: Anyone seen DAX?

Post by Tom Denham »

Rick Brown wrote:Wait, this isn't about Star Trek/DS9?

:lol:
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Mark DeShon
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Re: Anyone seen DAX?

Post by Mark DeShon »

Jeff Stuart wrote: In the thread discussing this on sccaforums (http://www.sccaforums.com/forums/aft/444834" onclick="window.open(this.href);return false;) there are people pointing out that by only considering data from national events on good, rubbered in courses, these numbers wouldn't necessarily be fair when used for regional events at sites that probably have less grip on average, which I think is a valid point.
My humble opinion is that this point is only really valid at National Championships. That's the only time that the same courses get enough cars run over them at different times to create an imbalance between classes. My $.02
I figured this sort of thing was coming soon. I wonder how long before we start using it or something like it. All controversy aside, everyone in SCCA Solo owes Rick a huge 'Thank You' for his efforts over the years. Perfect or not, everyone uses the PAX index to some degree.
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Craig Naylor
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Re: Anyone seen DAX?

Post by Craig Naylor »

Jeff Stuart wrote:He pulled data from 2012 and 2013, and only National Championships and National Tour data.

You won STS at the 2013 SD Tour, so I agree I would've expected to see you in the listing. Lily was at the 2012 SD Tour, so that's how she got in there, perhaps the 2013 SD Tour was left out?

Are there any other of those ^ events that you were at?
What Data is used? This version uses data from all SCCA National Solo events from the 2012 and 2013 seasons. Each event day was treated as a separate event to increase the data pool
From his stated inclusion events, I would have 6 event days. '13 SD Tour, '13 El Toro Pro, '13 ST George MT out of 51. Lilly has 2, '12 SD Tour. Again my point isn't my exclusion, though admittedly I looked because I was curious what my Driver index would be... but rather what "magic" is he using as he chooses who is in and who is out. The fact people are being removed... means the data is being manipulated. IMHO, that makes it no different than the RTP so far as manipulation goes.
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Re: Anyone seen DAX?

Post by Jeff Stuart »

Craig Naylor wrote: From his stated inclusion events, I would have 6 event days. '13 SD Tour, '13 El Toro Pro, '13 ST George MT out of 51. Lilly has 2, '12 SD Tour. Again my point isn't my exclusion, though admittedly I looked because I was curious what my Driver index would be... but rather what "magic" is he using as he chooses who is in and who is out. The fact people are being removed... means the data is being manipulated. IMHO, that makes it no different than the RTP so far as manipulation goes.
I agree, I would like to know more about how the data that is included is chosen. However, I'm guessing in this case it's not going to be "magic", it's going to be a formula that decides to include results based on how many participated in the class for a given event, and perhaps other factors. Also, I don't think he's including ProSolo events as a source of data.
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Jeff Stuart
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Re: Anyone seen DAX?

Post by Jeff Stuart »

From the guy behind DAX:
"DPI is limited to drivers that faced 24 competitors at national events from 2012 to 2013"
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Re: Anyone seen DAX?

Post by Jeff Stuart »

Resurrecting this...

The draft ProSolo rules for this year are up, and they've elected to use the ProSolo version of DAX (ProDAX) rather than a modified PAX for their indexing: http://scca.cdn.racersites.com/prod/ass ... 0draft.pdf" onclick="window.open(this.href);return false;

Here's the link to the DAX/ProDAX spreadsheet again: https://docs.google.com/spreadsheet/pub ... blE&gid=48" onclick="window.open(this.href);return false;

Also, if anyone has some freshly popped popcorn, and an interest some quality PAX drama, I would recommend this thread over at sccaforums: http://www.sccaforums.com/forums/aft/44513" onclick="window.open(this.href);return false;
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Marshall Grice
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Re: Anyone seen DAX?

Post by Marshall Grice »

i've re-calculated some results from last years pro solo events and i think the new psi factors are pretty close. i mean i guess they should be since last years data IS the basis for the index.

anyone else notice that there is a planned *MIDYEAR INDEX CHANGE* schedule for june, after the spring nats pro solo? not looking forward to that at all.
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Jeff Stuart
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Re: Anyone seen DAX?

Post by Jeff Stuart »

For anyone else who couldn't figure out where Marshall read that ^

http://www.solomatters.com/explained_2014_prosolo_rules" onclick="window.open(this.href);return false;
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Re: Anyone seen DAX?

Post by Mark DeShon »

Marshall Grice wrote:i've re-calculated some results from last years pro solo events and i think the new psi factors are pretty close. i mean i guess they should be since last years data IS the basis for the index.

anyone else notice that there is a planned *MIDYEAR INDEX CHANGE* schedule for june, after the spring nats pro solo? not looking forward to that at all.
Meaning don't kick too much but earlier in the year.
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Leonard Cachola
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Re: Anyone seen DAX?

Post by Leonard Cachola »

Made a couple more calculators for you bench racers out there:

With DAX values:
http://www.lcachola.com/2014DAX.html

With DAXProSolo values:
http://www.lcachola.com/2014ProSolo.html
~Leonard Cachola
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Jeff Stuart
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Re: Anyone seen DAX?

Post by Jeff Stuart »

So it appears that a sufficient amount people complained loud enough that they changed their minds and they're going to use Rick Ruth's ProSolo PAX instead of ProDAX this year.

The final ProSolo rules are here: http://scca.cdn.racersites.com/prod/ass ... 0Doug4.pdf" onclick="window.open(this.href);return false;
Rick Ruth's ProSolo PAX values are here: http://home.comcast.net/~paxrtp/pro2014.html" onclick="window.open(this.href);return false;

Sorry Leonard!
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Leonard Cachola
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Re: Anyone seen DAX?

Post by Leonard Cachola »

Jeff Stuart wrote:So it appears that a sufficient amount people complained loud enough that they changed their minds and they're going to use Rick Ruth's ProSolo PAX instead of ProDAX this year.

The final ProSolo rules are here: http://scca.cdn.racersites.com/prod/ass ... 0Doug4.pdf" onclick="window.open(this.href);return false;
Rick Ruth's ProSolo PAX values are here: http://home.comcast.net/~paxrtp/pro2014.html" onclick="window.open(this.href);return false;

Sorry Leonard!
np. Easy to change.
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Leonard Cachola
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Re: Anyone seen DAX?

Post by Leonard Cachola »

Updated with the 2014 Pro Solo Index values:

http://www.lcachola.com/2014ProSolo.html
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