The rules
Every ranking dispute ends here. These rules are applied identically to every club, by code, from public data.
- R1Who counts as a graduate
- A player is a graduate of a club if he was registered there — youth or senior — for a total of 3 seasons (36 months) between his 15th and 21st birthdays. That's the UEFA "club-trained" standard, applied to every club the same way.
- R2Loans don't count
- Time spent out on loan doesn't count toward the 36 months. Being parked at a feeder club is not being trained at the academy.
- R3A player can be two academies' pride
- Trained three seasons at two different clubs? He appears in both XIs, with an "also trained at" note. That's reality, and yes, it fuels the argument on purpose.
- R4When the paperwork is fuzzy
- If exact registration dates are missing but sources list the player in the club's youth section for at least two seasons, he's in — marked as medium confidence (the * you see in the tables).
- R5-R6Still playing
- A graduate counts if he currently has a professional club, anywhere in the world, any division. Free agents get a 12-month grace period.
- R7-R8No striker at centre-back
- Every player gets exactly one position group — GK, DEF, MID or FWD — resolved from public records, never from whichever assignment inflates a club's total. Genuine errors are fixed through a public override file, each with a written reason.
- R9-R11What a player is worth
- If he was bought for a real, disclosed fee in the last 36 months, that fee is his value — badge FEE, with the date and clubs. Otherwise it's our estimate — badge EST — from a gradient-boosted model trained on disclosed transfer fees (age, position, caps, club strength, market timing), with its honest mean error published below. When the model lacks the data for a player, a simple published formula steps in: age curve × position × club strength, boosted by senior caps. No naked numbers, ever: every value carries its badge.
- R12-R14How the XI is built
- We try seven legal shapes (4-3-3, 4-4-2, 3-5-2, 3-4-3, 5-3-2, 4-5-1, 5-4-1), fill each line with the highest-valued eligible graduates, and keep the most valuable eleven. If an academy has no active keeper, the slot stays empty and the club is ranked anyway, flagged with a short XI. The penalty is natural and the display is honest.
- R15-R16The ranking
- Clubs are ranked by total XI value. We also show the graduate count, the Academy GDP (value of all active graduates), and average XI age. Data refreshes weekly — daily during the transfer windows, because that's when it gets spicy.
Where the data comes from
Wikidata (CC0) and Wikipedia (CC BY-SA) for careers, transfers and positions; ClubElo and league tables for club strength. No Transfermarkt data anywhere in the pipeline — this ranking is built entirely from openly licensed sources, and our output is open in return: full dataset and code under CC BY-SA 4.0, attribution “Onze Maison & Wikipedia contributors”.
Our estimates carry a published mean error of €17.9m — measured on the last 120 days of real, disclosed fees the model never saw. Judge us.
Marked in public
A published error rate is a promise; this is the receipt. Every time a graduate we had valued actually transfers, the estimate that was standing before the move goes up against the fee that was really paid — with the gap, the date and the source. The track record keeps all of it, the good calls and the embarrassing ones.
Spotted a mistake?
Eligibility calls, wrong positions, missing graduates — open an issue. Corrections ship with the next weekly refresh, each recorded in a public override file with its reason.
Data as of 2026-08-02 · rules phase0-r1r16-v1 · values gbt-v2. Not affiliated with any club, league or federation.