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BRI question

PostPosted: Mon Jan 24, 2011 10:43 am
by Jackie C
Here's a question....if Boxster Spec and 944 Spec are classed into CC12? for BRI purposes, and I beat them, shouldn't I be higher on the BRI? Can the powers that be explain this? Killer weekend. Couldn't have been better. Kudos to those who made it run smoothly.

Re: BRI question

PostPosted: Mon Jan 24, 2011 12:04 pm
by ttweed
Jackie C wrote:Here's a question....if Boxster Spec and 944 Spec are classed into CC12? for BRI purposes, and I beat them, shouldn't I be higher on the BRI? Can the powers that be explain this? Killer weekend. Couldn't have been better. Kudos to those who made it run smoothly.

Jackie-
I am not the "powers that be" and know nothing about how the BRI is structured for the new classes, but looking at the results, 944 Spec has the same index as CC11, at 0.9380, not CC12, which is 0.9280. Don't know if that is an error or what...

TT

Re: BRI question

PostPosted: Mon Jan 24, 2011 12:06 pm
by Jackie C
ok, whatever the class is, we are in the same class, so that would appear to be a glitch? hopefully?

Re: BRI question

PostPosted: Mon Jan 24, 2011 3:38 pm
by ttweed
Jackie C wrote:ok, whatever the class is, we are in the same class, so that would appear to be a glitch? hopefully?

I don't see anywhere that the BRI for the new classes has been published yet. Tom B. was asking people to report how their BSR, BSX and 944Spec cars would point out in the new classes so that he could come up with an index for them in this previous thread:
http://forum.pcasdr.org/forum/viewtopic.php?f=1&t=4545

It looks like people were coming up with classes of anywhere from CC8 to CC12 for these cars, depending on whether they were optimized or not (biggest question was weight reduction). In the SOW results, it looks like BSX was assigned the same index as CC12 while 944Spec got the same index as CC11. There were no BSR entrants at SOW in the results, so i don't know what index they were assigned.

In our old TT BRI, the 944Spec and BSX classes had the same index of 1.04. I'm not sure how they ended up different in the new system, but Tom B. could probably clarify if it was intentional or a typo. I also don't know if we are maintaining two indexes still, one for TT and one for AX. GGR has only one PAX index, but solved the AX/TT disparity by having different penalty points for TT vs. AX, so that the same car could end up in different classes for AX than for big track events. We haven't done that--there is only one set of penalty points in our system, so I am guessing we would have to maintain the dual BRI indexes to account for the different speed potential of cars on a short course vs. a long one.

just guessing here,
TT

Re: BRI question

PostPosted: Mon Jan 24, 2011 5:03 pm
by Cajundaddy
Jackie C wrote:Here's a question....if Boxster Spec and 944 Spec are classed into CC12? for BRI purposes, and I beat them, shouldn't I be higher on the BRI? Can the powers that be explain this? Killer weekend. Couldn't have been better. Kudos to those who made it run smoothly.


No no I am sure the BRI numbers are absolutely accurate ;) Nice finish there missy!

Re: BRI question

PostPosted: Mon Jan 24, 2011 9:58 pm
by Jad
The fact that there are 5 different classes in the top 5, at least gives some credit to the system. They ranged from cc6 to cc12, so it seems anyone could do well. Of course I might be slightly biased :wink:

I have to say I think the new classes are a lot more fun. there were about 11 cars that ran in cc6 for the weekend in a wide variety of cars.

Re: BRI question

PostPosted: Mon Jan 24, 2011 11:22 pm
by tb911
Yes, the BRI numbers are just the GGR PAX numbers, for SS and CC classes.
Lacking anything else, it is a good start, I guess.
For the classes that GGR doesn't have (944 Spec, etc.) I did ask for input to try to determine what CC class they were equivalent to and from there plugged in that number. It's only as good as the data I received and how I interpreted it. Of course, since our modification points are different from GGR's, it may be that the PAX numbers don't really correlate like they should for any of the classes.

The old BRI was determined through some statistical analysis of results for the various classes using historical data, I think by Carl & Otto, for AX & TT respectively. It is quite possible that until we have the data and someone steps up to do that again, the BRI may be fairly meaningless and useless.

Re: BRI question

PostPosted: Tue Jan 25, 2011 8:05 am
by Mmagus
tb911 wrote:The old BRI was determined through some statistical analysis of results for the various classes using historical data, I think by Carl & Otto, for AX & TT respectively. It is quite possible that until we have the data and someone steps up to do that again, the BRI may be fairly meaningless and useless.


BRI has always been a mystery to me and continues to be so in this case. I just gave up on a good BRI a while back. Looking at the historical data for the class I ran (GSS/CC15) I was thankfully able to manage a time 4.08 seconds faster that the previous record, yet that still lands me 32nd in BRI.

Lets look at it another way. Since BRI is, in therory, supposed to make all cars equal then the therory should hold that you could switch drivers to achieve times. Here is what I mean.

Jad's adjusted time is 1:19:41 mine is 1:27:03, a difference of 7.62 seconds. Which means that you should be able to put Jad in my car and he would be able to run a lap time 7.62 seconds faster than I did.

My raw time was 1:37:35, so he should have to have been able to lay down a raw time of 1:29:73. That time would have been just .61 behind Jackie's record setting pace in a full spec car. I KNOW Jad is a fantastic driver, take nothing away from his ability, his advice helped me achieve the time I did, but I really can't see how that could happen.

I fully admit, I may just not be looking at this properly, or may misunderstand the whole process. In my mind, for my class of car, BRI has been and continues to be as Tom said, "fairly meaningless and useless". I think I'll keep following Paul's advice, just have fun and drive, because to do otherwise becomes an exercise in frustration.

Re: BRI question

PostPosted: Tue Jan 25, 2011 11:28 am
by bibbetson
Mark,

Try and look at the BRI as a yardstick and not so much as an absolute. Use it as a basis for comparison to see if you are gaining spots on a few other known consistent drivers. Also, look at the groupings and for big gaps. By all means, don't get frustrated with it and stop using it as a tool. For this event a corrected time of 1:22.xx put you in the top 10 with some very good company. For example, had you been able to pull off a 1:32 you would have made the top 10 of the BRI. Was a 1:32 possible for your car? I really don't have a clue, but you need to ask yourself how well prepared your car is. Do you have the absolute best tires for your class. Where they in 100% perfect condition? (Did you see the Duncan's put on new sticker tires before timed runs?) I changed to better older tires and dropped 3+ seconds. Is your car utilizing 100% of the points the class allows? There is also HP and track design to consider. I gave up comparing myself to the Duncan's machine in general a long time ago and I won't think of using Otto as a yardstick at Big Willow.

The longer I attend driving events (15+ years of AX and 5+ years of TT), the more I come to realize that there is always time left on the track - a LOT of time. That time can either be in driving technique or car setup or most likely both. Keep driving and keep learning about car setup. Some day you will look at your BRI and say "now that's better..."

Re: BRI question

PostPosted: Tue Jan 25, 2011 11:33 am
by Don Middleton
Mmagus wrote:Jad's adjusted time is 1:19:41 mine is 1:27:03, a difference of 7.62 seconds. Which means that you should be able to put Jad in my car and he would be able to run a lap time 7.62 seconds faster than I did.

My raw time was 1:37:35, so he should have to have been able to lay down a raw time of 1:29:73. That time would have been just .61 behind Jackie's record setting pace in a full spec car. I KNOW Jad is a fantastic driver, take nothing away from his ability, his advice helped me achieve the time I did, but I really can't see how that could happen.

I fully admit, I may just not be looking at this properly, or may misunderstand the whole process. In my mind, for my class of car, BRI has been and continues to be as Tom said, "fairly meaningless and useless". I think I'll keep following Paul's advice, just have fun and drive, because to do otherwise becomes an exercise in frustration.


Excellent observation, Mark. That is precisely been the problem with the BRI. The BRI on our older system had many of the same "holes' in it, but none as dramatic as what you have pointed out with the new 2012 system BRI. Clearly, this new system needs a lot of work.

Paul's sage advice is best taken. Drive and have fun. If you get too frustrated, you might find yourself taking on the fixing/maintaining of the new BRI. :wink:

Re: BRI question

PostPosted: Tue Jan 25, 2011 1:20 pm
by mrondeau
bibbetson wrote:Mark,

Try and look at the BRI as a yardstick and not so much as an absolute. Use it as a basis for comparison to see if you are gaining spots on a few other known consistent drivers. Also, look at the groupings and for big gaps. By all means, don't get frustrated with it and stop using it as a tool. For this event a corrected time of 1:22.xx put you in the top 10 with some very good company. For example, had you been able to pull off a 1:32 you would have made the top 10 of the BRI. Was a 1:32 possible for your car? I really don't have a clue, but you need to ask yourself how well prepared your car is. Do you have the absolute best tires for your class. Where they in 100% perfect condition? (Did you see the Duncan's put on new sticker tires before timed runs?) I changed to better older tires and dropped 3+ seconds. Is your car utilizing 100% of the points the class allows? There is also HP and track design to consider. I gave up comparing myself to the Duncan's machine in general a long time ago and I won't think of using Otto as a yardstick at Big Willow.

The longer I attend driving events (15+ years of AX and 5+ years of TT), the more I come to realize that there is always time left on the track - a LOT of time. That time can either be in driving technique or car setup or most likely both. Keep driving and keep learning about car setup. Some day you will look at your BRI and say "now that's better..."


+1 - Use it as a yardstick. When I first started running TT's, I thought there was no way to ever get in the top 10 in BRI because all the high horsepower cars have such an advantage. Turns out that each track has advantages and disadvantages for every car type. Keep driving and see how much better you can do compared to the "yardstick" drivers that you are comparing yourself too. You'll be amazed at what consistent seat time will do for your driving.