What changed
- A skin evenness gene. A new `evenness` gene (the average of two rolls, so most koi are middling) sets how even a koi's colour and lustre are from nose to tail. It's rolled after every other gene, so older seeds keep theirs.
- You can see it. Patchy skin has broad soft areas of stronger and weaker colour. On a metallic koi, the shine thins out in dull patches in the same places. The patchiest koi also carry shimi, up to eight small dark freckles anywhere on the body or head. Even koi look exactly as before. It's a new `Blemishes` layer, so breakdowns can switch it off.
- Judges mark it down. Every koi's report has a new `even` part. Shimi on the head lower `head` (a quarter each), and shimi on the body lower `clear` (a tenth each). The weakest-part cap then makes a badly blemished koi Pond however good the rest is.
- Solid koi are judged harder. Ogon, Asagi, Bekko and other koi with no pattern to judge used to be scored on skin finish and body alone, so about 10% of Ogon reached Champion against 3% of Kohaku. Now they're scored on body (25%), finish (40%) and evenness (35%, the raw gene, strict), with shimi counting through the cap. Champions are now equally rare (4% of Kohaku, 4% of Ogon). In the middle of the range solids still grade a little better, because a Kohaku has more ways to go wrong.
- Faults judged from true shapes. The finish gene changes how soft and ragged patch edges are, and that was moving red onto a fin or into the odome as finish improved, so a cleaner koi could grade lower. The fault checks now use each patch's true shape with a crisp edge, so finish only counts as finish.
- Grade lines re-set to keep about 40% Pond, 32% Fine, 22% Show and 5% Champion (Fine from 0.505, Show from 0.66, Champion from 0.8).
Why
After the judge-style grading went in, patterned koi graded much harder than solids. That much is realistic: breeders cull most of every Kohaku spawn. But solid koi were far too easy, because we only judged their finish and body. A real judge looks just as hard at a solid koi: even colour and lustre from nose to tail, a clean head, no blemishes. Evenness and shimi give solid koi real ways to fail, and give the grade something you can see.
