US Handicap Weight Adjustment White Paper

[[email protected]]

A new file has been placed in the Contest Rules and Process section of the SSA web site describing the study of the effect of flying weight on handicaps.
It shows the basis for the recently proposed rules change that will be effective in 2019.
It may be found at the top of the listing under important reading.
Thanks to Andy Blackburn for many hours on this project.
For the Handicap Subcommittee
UH

[[email protected]]

On Thursday, January 31, 2019 at 12:22:20 PM UTC-5, Tom Kelley #711 wrote:
> On Tuesday, January 29, 2019 at 4:47:46 PM UTC-7, wrote:
> > A new file has been placed in the Contest Rules and Process section of the SSA web site describing the study of the effect of flying weight on handicaps.
> > It shows the basis for the recently proposed rules change that will be effective in 2019.
> > It may be found at the top of the listing under important reading.
> > Thanks to Andy Blackburn for many hours on this project.
> > For the Handicap Subcommittee
> > UH
>
> Question for Hank. Why is the new handicap system even needed when the below pilots poll results wish differently?
>
> 9.1 Do you favor adopting the European Handicapping system?
> (This system is currently use for OLC flights.)
> Yes 114
> 60%
> No 56
> 30%
>
> Best #711.

A new handicapping "system" isn't needed. What is needed and addressed is the need no more accurately reflect the effect of weight change on XC speed, and thus, scores.
We did do a comparison of the German handicap list and found ours and theirs to be very similar with very few exceptions. The US list is more detailed in terms of variants of individual types and includes a number of ships not on the other list.
The US list also is integrated into the registration and scoring system. Wholesale replacement would involve considerable work for little if any benefit.
Our "system" also adjusts for weight changes. This is done at the FAI level only in Club and 20M (not in 20M at WGC).
UH

[David Leonard]

On 1/31/2019 6:03 PM, wrote:
> On Thursday, January 31, 2019 at 12:22:20 PM UTC-5, Tom Kelley #711 wrote:
>> On Tuesday, January 29, 2019 at 4:47:46 PM UTC-7, wrote:
>>> A new file has been placed in the Contest Rules and Process section of the SSA web site describing the study of the effect of flying weight on handicaps.
>>> It shows the basis for the recently proposed rules change that will be effective in 2019.
>>> It may be found at the top of the listing under important reading.
>>> Thanks to Andy Blackburn for many hours on this project.
>>> For the Handicap Subcommittee
>>> UH
>>
>> Question for Hank. Why is the new handicap system even needed when the below pilots poll results wish differently?
>>
>> 9.1 Do you favor adopting the European Handicapping system?
>> (This system is currently use for OLC flights.)
>> Yes 114
>> 60%
>> No 56
>> 30%
>>
>> Best #711.
>
> A new handicapping "system" isn't needed. What is needed and addressed is the need no more accurately reflect the effect of weight change on XC speed, and thus, scores.
> We did do a comparison of the German handicap list and found ours and theirs to be very similar with very few exceptions. The US list is more detailed in terms of variants of individual types and includes a number of ships not on the other list.
> The US list also is integrated into the registration and scoring system. Wholesale replacement would involve considerable work for little if any benefit.
> Our "system" also adjusts for weight changes. This is done at the FAI level only in Club and 20M (not in 20M at WGC).
> UH
>


Might also note that the OLC has two (at least, I don't know all the
scoring subcategories), one for distance and a second far more
compressed variant for the speed competitions. Which one was preferred
by the poll? Of course there is no one "European Handicapping system"
unless you think of dividing the performance by a handicap factor as
European and multiplying by a handicap factor as being the backwards US
system.

ZL

[[email protected]]

On Tuesday, January 29, 2019 at 6:47:46 PM UTC-5, wrote:
> A new file has been placed in the Contest Rules and Process section of the SSA web site describing the study of the effect of flying weight on handicaps.
> It shows the basis for the recently proposed rules change that will be effective in 2019.
> It may be found at the top of the listing under important reading.
> Thanks to Andy Blackburn for many hours on this project.
> For the Handicap Subcommittee
> UH

If we are going to go to this direction what about also Windicapping? You can read all the igc files for the hours of the competition and figure out what the average wind speed was. Measured data are better than predictions.
avg climb rates and or avg L/D is computable also.

The white paper on the weight adjustment looks like a step in the right direction.

Chris

[krasw]

There is no "European handicaps", pretty much every country has it's own. You do know that Europe is not a country, do you?

[Retting]

“There is no "European handicaps", pretty much every country has it's own. You do know that Europe is not a country, do you? “ says rsw


If you’re going to get nieprzyjemny, improve your grammar do you! “ tępak! “

R

[Robin Clark]

On Thursday, January 31, 2019 at 10:19:14 PM UTC-5, wrote:
> On Tuesday, January 29, 2019 at 6:47:46 PM UTC-5, wrote:
> > A new file has been placed in the Contest Rules and Process section of the SSA web site describing the study of the effect of flying weight on handicaps.
> > It shows the basis for the recently proposed rules change that will be effective in 2019.
> > It may be found at the top of the listing under important reading.
> > Thanks to Andy Blackburn for many hours on this project.
> > For the Handicap Subcommittee
> > UH
>
> If we are going to go to this direction what about also Windicapping? You can read all the igc files for the hours of the competition and figure out what the average wind speed was. Measured data are better than predictions.
> avg climb rates and or avg L/D is computable also.
>
> The white paper on the weight adjustment looks like a step in the right direction.
>
> Chris

Whenever I think about Windicapping, I think about poor Daniel Sazhin in a 1-26 on a ridge day.
Robin

[BobW]

On 2/1/2019 8:02 AM, Robin Clark wrote:
<snip...>
>
> Whenever I think about Windicapping, I think about poor Daniel Sazhin in a
> 1-26 on a ridge day.
Funny! You and Sebastian Kawa! Every time I've had my soaring butt handed to
me on a platter, I've always figgered I deserved it!

Bob - I'll go back to lurking, now - W.

---
This email has been checked for viruses by AVG.
https://www.avg.com

[Andy Blackburn[_3_]]

On Thursday, January 31, 2019 at 8:51:11 AM UTC-8, wrote:
> On Tuesday, January 29, 2019 at 6:47:46 PM UTC-5, wrote:
> > A new file has been placed in the Contest Rules and Process section of the SSA web site describing the study of the effect of flying weight on handicaps.
> > It shows the basis for the recently proposed rules change that will be effective in 2019.
> > It may be found at the top of the listing under important reading.
> > Thanks to Andy Blackburn for many hours on this project.
> > For the Handicap Subcommittee
> > UH
>
> As a lightweight pilot flying a lightweight glider (i.e., at a W/Wref that is much below 1.0) I couldn't help but notice that the curves in the white paper only show weights higher than the reference weight (except for the Arcus M graph on page 5). I hope that the theory (and the proposed rule) generally work OK for weights lower than the reference weight.
>
> Also, it seems to me that, for gliders on the low end of the wing loading range (within those that actually compete in contests), the differences in XC speed between gliders of same model due to weight variability are small relative to the differences between models due to weather factors such as wind and thermal height.

The answer to your questions are yes and yes.

The old weight adjustment formula was a linear approximation that didn't work especially well for large variations in W/Wref or for very high or very low Wref values, because it was; 1) a linear approximation and 2) centered on a single Wref value. The new one should be a better fit across a wider range of gliders and weights. We have not elected to pursue weather adjustments at this time, but it is being evaluated. PM me if you want to see some preliminary work on the subject.

To summarize, there is no single handicapping system that is: 1) perfectly equitable, 2) perfectly simple, 3) perfectly adapted to all soaring conditions.

It's true that there are a number of different handicapping schemes in use around the world. The primary issue we face in the US (though there are more than one) is the we have Sports Class which allows motor gliders, 2-seaters and a wide range of handicaps. If we want to continue to have Sports Class we need a more accurate and robust weight adjustment formula. It could be based on one of the base handicap systems in use in Europe (as UH mentioned, the US system is very similar) with a more robust weight adjustment formula if: a) that base system included all the relevant gliders (we could add to it if not) and, b) there was some analytical backup available for how the base handicaps are set (Wref in particular, but also the quadratic polar parameters would be nice as well as the Mc value that the handicap was centered on).

Alternatively, we could drop Sports Class or drop weight adjustments (which would lead to a lot of people flying with a bunch of fixed ballast and complaints about the equity/safety of such behavior I suspect). We've not opted for that because people seem to like Sports Class (see poll) and weight adjustments are more equitable, though not as equitable as weight plus weather adjustments (but at the expense of item 2) above). Again, we're looking at that, but it's an immense amount of work and will take time.

I'd add you can't typically take a single poll result and promote it as the definitive answer to a complex set of issues. If you read the full poll and comments in their totality, answers to many individual questions tend to contradict each other either in whole or in part. The answer on handicapping seems to be to not re-invent the wheel versus the rest of the world, but also to adapt global standards where necessary to preserve things we care about (e.g. Sports Class). We're working on that. This year is just a first step in doing some cleanup, but there is more to do - depending on how pilots want to trade off items 1), 2) and 3).

Andy Blackburn
9B
Chair, SSA Competition Rules Committee

[[email protected]]

On Friday, February 1, 2019 at 1:56:00 PM UTC-5, Andy Blackburn wrote:
> On Thursday, January 31, 2019 at 8:51:11 AM UTC-8, wrote:
> > On Tuesday, January 29, 2019 at 6:47:46 PM UTC-5, wrote:
> > > A new file has been placed in the Contest Rules and Process section of the SSA web site describing the study of the effect of flying weight on handicaps.
> > > It shows the basis for the recently proposed rules change that will be effective in 2019.
> > > It may be found at the top of the listing under important reading.
> > > Thanks to Andy Blackburn for many hours on this project.
> > > For the Handicap Subcommittee
> > > UH
> >
> > As a lightweight pilot flying a lightweight glider (i.e., at a W/Wref that is much below 1.0) I couldn't help but notice that the curves in the white paper only show weights higher than the reference weight (except for the Arcus M graph on page 5). I hope that the theory (and the proposed rule) generally work OK for weights lower than the reference weight.
> >
> > Also, it seems to me that, for gliders on the low end of the wing loading range (within those that actually compete in contests), the differences in XC speed between gliders of same model due to weight variability are small relative to the differences between models due to weather factors such as wind and thermal height.
>
> The answer to your questions are yes and yes.
>
> The old weight adjustment formula was a linear approximation that didn't work especially well for large variations in W/Wref or for very high or very low Wref values, because it was; 1) a linear approximation and 2) centered on a single Wref value. The new one should be a better fit across a wider range of gliders and weights. We have not elected to pursue weather adjustments at this time, but it is being evaluated. PM me if you want to see some preliminary work on the subject.
>
> To summarize, there is no single handicapping system that is: 1) perfectly equitable, 2) perfectly simple, 3) perfectly adapted to all soaring conditions.
>
> It's true that there are a number of different handicapping schemes in use around the world. The primary issue we face in the US (though there are more than one) is the we have Sports Class which allows motor gliders, 2-seaters and a wide range of handicaps. If we want to continue to have Sports Class we need a more accurate and robust weight adjustment formula. It could be based on one of the base handicap systems in use in Europe (as UH mentioned, the US system is very similar) with a more robust weight adjustment formula if: a) that base system included all the relevant gliders (we could add to it if not) and, b) there was some analytical backup available for how the base handicaps are set (Wref in particular, but also the quadratic polar parameters would be nice as well as the Mc value that the handicap was centered on).
>
> Alternatively, we could drop Sports Class or drop weight adjustments (which would lead to a lot of people flying with a bunch of fixed ballast and complaints about the equity/safety of such behavior I suspect). We've not opted for that because people seem to like Sports Class (see poll) and weight adjustments are more equitable, though not as equitable as weight plus weather adjustments (but at the expense of item 2) above). Again, we're looking at that, but it's an immense amount of work and will take time.
>
> I'd add you can't typically take a single poll result and promote it as the definitive answer to a complex set of issues. If you read the full poll and comments in their totality, answers to many individual questions tend to contradict each other either in whole or in part. The answer on handicapping seems to be to not re-invent the wheel versus the rest of the world, but also to adapt global standards where necessary to preserve things we care about (e.g. Sports Class). We're working on that. This year is just a first step in doing some cleanup, but there is more to do - depending on how pilots want to trade off items 1), 2) and 3).
>
> Andy Blackburn
> 9B
> Chair, SSA Competition Rules Committee

Thanks Andy, for your answer and for all your work on the issue.

A question on the practical aspect: to implement weight-adjusted handicaps, would all gliders at a contest need to be weighed? Or would the pilots' declared all-up flying weights be accepted without verification? Of course the honor system may let some cheating slip through. But a full weighing may be a significant burden on contest organizers, especially at the smaller regionals.

[[email protected]]

On Friday, February 1, 2019 at 2:29:58 PM UTC-5, wrote:
> On Friday, February 1, 2019 at 1:56:00 PM UTC-5, Andy Blackburn wrote:
> > On Thursday, January 31, 2019 at 8:51:11 AM UTC-8, wrote:
> > > On Tuesday, January 29, 2019 at 6:47:46 PM UTC-5, wrote:
> > > > A new file has been placed in the Contest Rules and Process section of the SSA web site describing the study of the effect of flying weight on handicaps.
> > > > It shows the basis for the recently proposed rules change that will be effective in 2019.
> > > > It may be found at the top of the listing under important reading.
> > > > Thanks to Andy Blackburn for many hours on this project.
> > > > For the Handicap Subcommittee
> > > > UH
> > >
> > > As a lightweight pilot flying a lightweight glider (i.e., at a W/Wref that is much below 1.0) I couldn't help but notice that the curves in the white paper only show weights higher than the reference weight (except for the Arcus M graph on page 5). I hope that the theory (and the proposed rule) generally work OK for weights lower than the reference weight.
> > >
> > > Also, it seems to me that, for gliders on the low end of the wing loading range (within those that actually compete in contests), the differences in XC speed between gliders of same model due to weight variability are small relative to the differences between models due to weather factors such as wind and thermal height.
> >
> > The answer to your questions are yes and yes.
> >
> > The old weight adjustment formula was a linear approximation that didn't work especially well for large variations in W/Wref or for very high or very low Wref values, because it was; 1) a linear approximation and 2) centered on a single Wref value. The new one should be a better fit across a wider range of gliders and weights. We have not elected to pursue weather adjustments at this time, but it is being evaluated. PM me if you want to see some preliminary work on the subject.
> >
> > To summarize, there is no single handicapping system that is: 1) perfectly equitable, 2) perfectly simple, 3) perfectly adapted to all soaring conditions.
> >
> > It's true that there are a number of different handicapping schemes in use around the world. The primary issue we face in the US (though there are more than one) is the we have Sports Class which allows motor gliders, 2-seaters and a wide range of handicaps. If we want to continue to have Sports Class we need a more accurate and robust weight adjustment formula. It could be based on one of the base handicap systems in use in Europe (as UH mentioned, the US system is very similar) with a more robust weight adjustment formula if: a) that base system included all the relevant gliders (we could add to it if not) and, b) there was some analytical backup available for how the base handicaps are set (Wref in particular, but also the quadratic polar parameters would be nice as well as the Mc value that the handicap was centered on).
> >
> > Alternatively, we could drop Sports Class or drop weight adjustments (which would lead to a lot of people flying with a bunch of fixed ballast and complaints about the equity/safety of such behavior I suspect). We've not opted for that because people seem to like Sports Class (see poll) and weight adjustments are more equitable, though not as equitable as weight plus weather adjustments (but at the expense of item 2) above). Again, we're looking at that, but it's an immense amount of work and will take time.
> >
> > I'd add you can't typically take a single poll result and promote it as the definitive answer to a complex set of issues. If you read the full poll and comments in their totality, answers to many individual questions tend to contradict each other either in whole or in part. The answer on handicapping seems to be to not re-invent the wheel versus the rest of the world, but also to adapt global standards where necessary to preserve things we care about (e.g. Sports Class). We're working on that. This year is just a first step in doing some cleanup, but there is more to do - depending on how pilots want to trade off items 1), 2) and 3).
> >
> > Andy Blackburn
> > 9B
> > Chair, SSA Competition Rules Committee
>
> Thanks Andy, for your answer and for all your work on the issue.
>
> A question on the practical aspect: to implement weight-adjusted handicaps, would all gliders at a contest need to be weighed? Or would the pilots' declared all-up flying weights be accepted without verification? Of course the honor system may let some cheating slip through. But a full weighing may be a significant burden on contest organizers, especially at the smaller regionals.

Tradition has been that the honor system is used at regionals. Nationals are required to have weighing capability. All ships are weighed at Sports and Club before flying to establish the contest handicap. After that check weighing is done at the discretion of the CD. Commonly the 3 top gliders from the previous day and the top few overall get weighed.
UH

[jfitch]

On Friday, February 1, 2019 at 12:06:27 PM UTC-8, wrote:
> On Friday, February 1, 2019 at 2:29:58 PM UTC-5, wrote:
> > On Friday, February 1, 2019 at 1:56:00 PM UTC-5, Andy Blackburn wrote:
> > > On Thursday, January 31, 2019 at 8:51:11 AM UTC-8, wrote:
> > > > On Tuesday, January 29, 2019 at 6:47:46 PM UTC-5, wrote:
> > > > > A new file has been placed in the Contest Rules and Process section of the SSA web site describing the study of the effect of flying weight on handicaps.
> > > > > It shows the basis for the recently proposed rules change that will be effective in 2019.
> > > > > It may be found at the top of the listing under important reading..
> > > > > Thanks to Andy Blackburn for many hours on this project.
> > > > > For the Handicap Subcommittee
> > > > > UH
> > > >
> > > > As a lightweight pilot flying a lightweight glider (i.e., at a W/Wref that is much below 1.0) I couldn't help but notice that the curves in the white paper only show weights higher than the reference weight (except for the Arcus M graph on page 5). I hope that the theory (and the proposed rule) generally work OK for weights lower than the reference weight.
> > > >
> > > > Also, it seems to me that, for gliders on the low end of the wing loading range (within those that actually compete in contests), the differences in XC speed between gliders of same model due to weight variability are small relative to the differences between models due to weather factors such as wind and thermal height.
> > >
> > > The answer to your questions are yes and yes.
> > >
> > > The old weight adjustment formula was a linear approximation that didn't work especially well for large variations in W/Wref or for very high or very low Wref values, because it was; 1) a linear approximation and 2) centered on a single Wref value. The new one should be a better fit across a wider range of gliders and weights. We have not elected to pursue weather adjustments at this time, but it is being evaluated. PM me if you want to see some preliminary work on the subject.
> > >
> > > To summarize, there is no single handicapping system that is: 1) perfectly equitable, 2) perfectly simple, 3) perfectly adapted to all soaring conditions.
> > >
> > > It's true that there are a number of different handicapping schemes in use around the world. The primary issue we face in the US (though there are more than one) is the we have Sports Class which allows motor gliders, 2-seaters and a wide range of handicaps. If we want to continue to have Sports Class we need a more accurate and robust weight adjustment formula. It could be based on one of the base handicap systems in use in Europe (as UH mentioned, the US system is very similar) with a more robust weight adjustment formula if: a) that base system included all the relevant gliders (we could add to it if not) and, b) there was some analytical backup available for how the base handicaps are set (Wref in particular, but also the quadratic polar parameters would be nice as well as the Mc value that the handicap was centered on).
> > >
> > > Alternatively, we could drop Sports Class or drop weight adjustments (which would lead to a lot of people flying with a bunch of fixed ballast and complaints about the equity/safety of such behavior I suspect). We've not opted for that because people seem to like Sports Class (see poll) and weight adjustments are more equitable, though not as equitable as weight plus weather adjustments (but at the expense of item 2) above). Again, we're looking at that, but it's an immense amount of work and will take time.
> > >
> > > I'd add you can't typically take a single poll result and promote it as the definitive answer to a complex set of issues. If you read the full poll and comments in their totality, answers to many individual questions tend to contradict each other either in whole or in part. The answer on handicapping seems to be to not re-invent the wheel versus the rest of the world, but also to adapt global standards where necessary to preserve things we care about (e.g. Sports Class). We're working on that. This year is just a first step in doing some cleanup, but there is more to do - depending on how pilots want to trade off items 1), 2) and 3).
> > >
> > > Andy Blackburn
> > > 9B
> > > Chair, SSA Competition Rules Committee
> >
> > Thanks Andy, for your answer and for all your work on the issue.
> >
> > A question on the practical aspect: to implement weight-adjusted handicaps, would all gliders at a contest need to be weighed? Or would the pilots' declared all-up flying weights be accepted without verification? Of course the honor system may let some cheating slip through. But a full weighing may be a significant burden on contest organizers, especially at the smaller regionals.
>
> Tradition has been that the honor system is used at regionals. Nationals are required to have weighing capability. All ships are weighed at Sports and Club before flying to establish the contest handicap. After that check weighing is done at the discretion of the CD. Commonly the 3 top gliders from the previous day and the top few overall get weighed.
> UH

This issue and formula probably affects the Truckee FAI regionals more than any other, as a wide variety of gliders are entered (Std Cirrus through JS1-21) and can be flown from at any weight from empty to MTOW. At Truckee every glider is weighed prior to declaration by the pilot on the first day, and he/she must fly the whole contest with that handicap. We have attempted to weigh all gliders every day, and often do.

In earlier years this contest was flown without handicap adjustment for weight, as can be seen from Andy's paper this gave heavily ballasted gliders a huge advantage. Weather at Truckee is typically stronger than the 3 knot benchmark, and often much stronger, making the advantage greater. I believe pilots were overall satisfied with the previous formula (the new one is not much different, except for some peculiar cases). I note that they almost universally load full of water, suggesting that a full load is still believed to be well worth the handicap adjustment.

[Tony[_5_]]

I think the true best way to ensure fairness wrt weight would be to greet pilots after landing. This is how Motorsports regulate, through post race inspection.

[Dan Daly[_2_]]

@Tony: Tongue in cheek? Water ballast is dropped before landing (required by most POHs).

[[email protected]]

On Saturday, February 2, 2019 at 1:30:10 PM UTC-5, Tony wrote:
> I think the true best way to ensure fairness wrt weight would be to greet pilots after landing. This is how Motorsports regulate, through post race inspection.

They did exactly that in my first WGC in Oz.
UH

[Andy Blackburn[_3_]]

On Saturday, February 2, 2019 at 1:57:25 PM UTC-8, wrote:
> On Saturday, February 2, 2019 at 1:30:10 PM UTC-5, Tony wrote:
> > I think the true best way to ensure fairness wrt weight would be to greet pilots after landing. This is how Motorsports regulate, through post race inspection.
>
> They did exactly that in my first WGC in Oz.
> UH

A fair amount of the efficacy of post-flight inspection would depend on whether you are doing it for Club or an FAI Class I would think.

Andy Blackburn
9B

[Tony[_5_]]

I was thinking about dry handicapped classes.

[Dan Daly[_2_]]

On Saturday, February 2, 2019 at 8:13:33 PM UTC-5, Tony wrote:
> I was thinking about dry handicapped classes.

My bad. Sorry!