The Breeding Index — how it works
Every stallion page carries a Breeding Index — one 0–100 score with a plain-English tier (Ascending, Peak, Established, Emerging, Fading). It exists to answer a breeder's real question: not just what has this sire produced, but where is he heading? Weights version v1.
The five components
World ranking (25%) — the WBFSH 2025 final list, turned into a percentage of the field beaten. Proven offspring (20%) — how many sons and daughters have jumped 1.60 m, on a curve where each extra horse counts a little less. Quality (15%) — offspring who have won at 5★. This season (15%) — the current-season world list against last year's. Next generation (25%) — the ages of his proven offspring: a young wave scores high, crops ageing out score low.
Forward-looking on purpose
40% of the full weight (this season + next generation) looks forward, not back. Two sires with identical career records can read very differently: one whose stars were born fifteen years ago, and one with nine-year-olds arriving at the top today. A plain career ranking cannot tell them apart; the index is built to.
Honest gaps — nothing is guessed
Each component only counts when its research has actually landed (our scouts run two independent AI models over cited sources, and keep only what both support). A missing component is excluded and the weights re-balance — it is never averaged in as a guess. That is why some pages say "our scouts are researching this horse".
Independence
No stud can pay for placement, a rank, or a higher index — the same rule as everything on EquiWiki. Scores are computed from the published data at build time, the weights are versioned and public, and any correction is recorded on the changelog. Decision support, not a guarantee.
See also: how EquiWiki is made — sourcing, verification and corrections.