That's just not right Dan.
SIZE is a catch all term. Length?
The reason koi are placed in sizes is to make competition fairer. This is not because the big fish always wins! It is because a koi show is a competition between fish of different ages. Small fish are judged against a different scale and standard than medium fish or large fish. Put another way, koi are judged differently depending on whether they are fry, young, pre-adult, adult and mature adult.
WITHIN any of these groupings, we have comformation competition considerations. In the small sizes, a male confirmation is perfectly acceptable. So the fact that a fish is slimmer than another in the small sizes does not put it out of the running. As long as 'thin' is still well within the framework of good male conformation.
It does sound nice to say a judge can go down a few sizes to award GC to the 'best' fish in a show. But that would be a horrible mistake if that meant the judge was crossing the line between mature adult and say, preadult.
It is true that 'large' is rare and often a sign of quality genetics. But a big fish should not win a show because it was big. Otherwise we could all be buying chagoi and be done with it!
Likewise, a koi should not win the entire show because it has great quality but is not mature yet ( you can insert 'large' here). That is not the description of a GC.
A place for everything and everything in it's place.
JR ( alive and kick'n, thanks)
JR