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