A dog's pedigree has a fixed number of ancestor slots. In 5 generations there are 62 slots; in 10 generations there are 2,046. ALC compares how many slots are filled by unique individual dogs versus how many slots exist.
This is also known as pedigree collapse. The acronym AVK comes from the German Ahnenverlust-Koeffizient and is widely used in European breeding literature.
ALC at 5 generations gives a focused view of recent breeding decisions. With 62 slots, individual repeated dogs are visible and identifiable — your quick check for tight linebreeding.
ALC at 10 generations provides the broader historical picture. With 2,046 possible slots, almost every dog will have some ancestor loss. A 10-generation ALC below 50% suggests significant pedigree collapse.
Dog (or Cat) → Genealogy → Inbreeding Analysis
ALC appears in two blocks (5 and 10 generations) with breakdowns of possible, found, unique, duplicated, and missing ancestors. Also shown on the Dog and Cat Overview screen and in exports.