The Outlier Index (OI) measures how unusual a dog’s allele combination is relative to the tested population of its breed. A higher OI means the dog carries alleles at lower frequencies across the breed — genetic variants that are underrepresented in the population as a whole.

Dogs with high OI are genetically valuable because they carry diversity that most other tested dogs don’t share. Breeding them thoughtfully into the broader population helps redistribute lower-frequency alleles rather than allowing them to become even rarer over generations.

Average Genetic Relatedness (AGR) measures how similar a dog’s DNA is, on average, to every other tested dog in the breed. It reflects the dog’s mean kinship — how closely related it is to the population as a whole.

A lower AGR means the dog is more genetically distinct from the majority of the breed. Dogs with low AGR carry alleles at lower frequencies across the tested population, making them higher-priority candidates for inclusion in a well-managed breeding program.

Internal Relatedness (IR) measures how much identical genetic material an individual dog inherited from both parents. IR is a useful indicator of inbreeding: lower IR generally reflects lower inbreeding, and it is widely used and reported in the scientific literature.

A high IR is not the cause for alarm it might appear. Elevated IR can often be resolved in a single generation by pairing with a dog whose ancestry is less represented in the breed. It is a signpost, not a sentence.

BetterBred reports IR for reference, but it is not our primary breeding guidance tool. OI and AGR together give a more complete and actionable picture of a dog’s genetic value to the population.