Methodology
One set of rules, written down once.
Definitions
- Sire
- The father in a ranking: leading sires, champion sire. Stallion is the same horse on the farm: stands at, roster, fee. Broodmare sire is the sire of the dam.
- Group 1 win
- A win in a race graded Group 1 or Grade 1 by its own jurisdiction, as listed in the G1Stars calendar. Counted per race; a dead heat counts for both. Season 2026 means calendar year 2026 to the data date.
- Individual winners
- Distinct horses with at least one Group 1 win in the period.
- Purse won
- The total purse of the races won, in EUR as shown on G1Stars. Not the winner's share.
- Yearling average
- Gross divided by yearlings sold, across all European sales in YearlingStars coverage for the year. Not sold, withdrawn and vendor buy-backs are excluded from the average and counted in "offered". Converted to EUR at the rate of the sale day (ECB), guineas at 1.05 GBP. A sire enters the ranking with at least 5 sold. This is the identical calculation to YearlingStars.
- Published fee
- The fee printed on the farm's official roster, fee card or fee announcement for the 2026 season. "Private", "POA" or "on application" is shown as Private and never ranked. Terms (Oct 1 SLF, live foal, inc GST, payable on pregnancy) are shown as the roster states them. Nothing is estimated or taken from press tables.
- Fee in EUR
- Converted at the ECB reference rate of 2026-09-25 for comparison only. The original currency is always shown first.
- Value
- Group 1 wins in 2026 divided by (published fee in EUR / 10,000). A lens, not advice.
- Regions
- Europe: GB, Ireland, France, Germany, Italy. North America: USA, Canada. Japan. Australia-NZ. Hong Kong, the Gulf and others count in World only. For fees the region is where the stallion stands; for Group 1 wins it is where the race was run.
Minimum numbers
Percentages are only shown with their denominator, and only above these thresholds: sales averages from 5 sold; broodmare-sire crosses (nicks) from 8 runners; otherwise the page says "Insufficient data". Foals, runners, winners, stakes winners, AEI and progeny earnings are not shown at all until licensed data is in place.
Sources
Group 1 results and calendar: G1Stars. Yearling sales: YearlingStars. Fees, standing farm, shuttle and status: the official website of each farm; every profile links its source. Currency: ECB euro foreign exchange reference rates. No tables are copied from other publications.
What SireStars is not
Not a stallion register with advertisements, not a newsroom, not a booking tool, not breeding advice. It shows what happened on the track, in the ring and on the roster, side by side, with the sums written out.