View Single Post
  #2  
Old December 17th 10, 04:33 PM posted to rec.aviation.soaring
John Cochrane[_2_]
external usenet poster
 
Posts: 237
Default USA 2010 Competition Rules Committee Minutes Posted


There is a scenario I can't quite figure under the new rule. *Say ALL
the finishers are MT15 and very short distances but a bunch of pilots
were able to rack up long distances but not get home. This can happen
with big weather systems moving through. The choice you have is stay
close to home so you can finish and risk a short flight or follow the
good conditions on the chance that you'll be able to get back home
later. I think under the new rules you might make the bet that none of
the long flights finish, but if even one of them succeeds it radically
changes the scoresheet because all the short finishers see their
scores cut down dramatically as BESTDIST goes dramatically up. Also
all the long non-finishers would see their scores go up if even one of
them gets home. It also potentially gets tangled up in devaluation
depending on the ratios.

I guess versus the old system it gives you some additional incentive
to be the hero and get around on a long flight even in dicey
conditions.

Any insights?

9B


That's pretty much right.

Important note: In US rules, when there are any "finishers", BESTDIST
is still calculated as the best distance a finisher achieves. BESTDIST
does not reflect very long landouts. Thus, if the "finishers" go 100
miles, but some other guys all go 400 miles and land out, BESTDIST is
still 100 miles. The long landouts still only get 100 miles of
distance points. This is a separate problem, which maybe we'll think
about fixing someday, or maybe not. (Changing that to BESTDIST = the
long landout leads to another can of worms in terms of unintended
clever strategies.) One at a time, this is confusing enough!

The new rule only changes the scores of very short "finishers" when
there are other faster finishers. That's a good principle to keep in
mind. For example, it does not change the scores of your long landouts
above, nor of the 400 mile guys if one of them makes it home.

The only change is, a slow finisher is guaranteed the best of HIS
distance points or his speed points, whereas he used to be guaranteed
the best BESTDIST distance points, or his speed points. That's it.

What happens then is pretty much what you describe. If none of the
400 mile guys make it back, the 100 mile guys win the day, and the 400
mile guys ony get distance points as if they flew 100 miles. (And the
day will be strongly devalued).

If one of the 400 mile guys squeaks back to the airport, under old
rules the 100 mile "finishers" would have gotten 630 points, equal to
a 399 mile landout. Under the new rule the 100 mile "finishers" will
get 100/400*600 + 30 = 180 points, just as if they had landed out at
an airport at 100 miles, plus 5 points extra.

So, as you describe, the change does not guarantee that going longer
will win the day. But it does rather substantially increase the odds
that going longer will pay off. If you make it back after going
longer, you'll destroy the scores of the 100 mile guys. If you landout
at 399 but someone else goes 400 miles and makes it back, then your
399 mile landout will be worth 599 (+25) points, and you will destroy
the 100 mile guys.

This is an important strategic consideration that pilots need to be
aware of. Keeping going under a TAT / MAT rather than stopping very
early--say 1 -2 hours into a 3 hour task--is now a much more
attractive option. It's almost back to the way you would have thought
about it under an AST, where you would not stop and land at an airport
along the way unless things were really pretty desperate. It's not
quite that much. There is still a bit stronger incentive to cut short
a TAT/MAT than an AST because, as you describe, you can gamble that
nobody goes longer and makes it back. But that gamble faces longer
odds than it used to.

I don't think of this as a "change" I think of it as "fixing an
uninteded bug in the rules." We were happy with the tradeoffs pilots
were making under AST regarding stopping at an airport or keeping
going. When we ported the scoring formulas to TAT/MAT, as I view it,
we inadvertently opened this clever strategy to go back after 1 hour
and guarantee yourself 630 points even if the winners do 400 miles.
Loophole now closed.

John Cochrane
BB