Inbreeding
coefficient
Wright's coefficient, F, for a pairing. Pick how the two birds are related and see what the chicks inherit, plus the cumulative effect of repeating it.
F is the probability that a chick receives two identical copies of the same ancestral gene. The app computes it from your real pedigree; this estimates it from a stated relationship.
Scale runs to 50%, the theoretical ceiling for repeated full-sibling mating.
Line-breeding is deliberate. Inbreeding is what happens by accident.
A single cousin pairing to fix a mutation is a normal tool, used knowingly and then outcrossed away from. The damage comes from a closed collection where nobody tracked who came from whom, and F climbed a few points every season for a decade.
Keeping a pedigree is what makes the difference, because you cannot see F by looking at a bird.
Mutation outcomes for the same pairing are on the mutation pairing calculator.
Get F from your own pedigree instead of a stated relationship.
See genetics in the app