FairValue

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  • EnvironmentOverviewWhat FairValue measures, what it found, where to go next.
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Abel

Bretones

LBSpain · CA Osasuna

№ 658115Established €3.2M +0.09

Player dossierLaLiga

AbelBretones

LBLeft-BackDefender

Club
CA Osasuna
League
LaLiga
Nationality
Spain
Age
25
Height
188 cm
Foot
Left
Valued
5 Jun 2026

Reading the valuation

The market values Bretones at €3.5M. Model A, which never saw Bretones during training, estimates €3.2M: the market value is 10% above that estimate.

That is a factor of ×1.10. Model A's typical held-out miss is ×1.50 either way, so this gap is within its usual error.

Without league and club, Model B estimates €5.1M, further from the market. Model B is usually further off (typical miss ×2.07): league and club explain much of how the market prices players.

A gap describes the model's arithmetic for this player's inputs, not what the player is worth.

▲ +0.09A €3.2M▼ −0.38B €5.1M
Pitch length is a log value scale fitted to this player's figures. ● observed · ◇ Model A · dashed ◇ Model B · each arc is a residual, log(observed) − log(estimate).
Apps
69
Minutes
4,098
Goals
3
Assists
2
Started
41/69
Min / app
59
Cards
8Y 0R

Club matches, two years to the valuation date

The Valuation Journey

What moves Model A

Asking the prediction API to explain Model A for Bretones…

SHAP describes the model's arithmetic for this player's inputs, not what causes market value. Model B can be explained only by the live service; Model A also has a published explanation for the research players.

Model A vs Model B against the observed €3.5M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €3.5MModel A €3.2M

Asking the prediction API…

Held-out estimates come from cross-validation, with this player outside the training data: the honest comparison. Served models were refitted on every player, this one included, so they sit closer to the market. Shaded band: Model A's typical miss (×1.50 either way).

Player traitspercentiles vs 2,065 defenders

Abel Bretones's percentiles among defenders: Goals per 90 73rd, Assists per 90 53rd, Minutes, two years 71st, Starts 15th, Minutes, last 365 days 52nd, European club minutes 30th73rdGoals53rdAssists71stMinutes15thStarts52ndRecent30thEurope

Dashed ring: the defender median (50th percentile)

Goals per 90

Club goals per 90 minutes played in the two years to the valuation date.

0.07 this player0.03 defender median73rd percentile

0.00peer deciles · median line · this player ●0.41

No passing, progression or defensive actions exist in the dataset, so no trait claims to measure them.

Valuation history every Transfermarkt valuation on record

First valuation
€50k
Sept 2019
Peak
€4.5M
Dec 2025
Model target
€3.5M
Jun 2026
Valuations
18
4 club changes
Jun 2026€3.5MCA OsasunaValuation the model is trained to reproduce

Jun 2026: €3.5M, CA Osasuna. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2019-09-10€50kUP Langreo B
2020-02-11€50kUP Langreo B
2021-03-19€50kUP Langreo
2021-06-30€50kUP Langreo
2021-12-30€50kUP Langreo
2022-09-26€200kReal Oviedo Vetusta
2022-12-29€400kReal Oviedo Vetusta
2023-03-24€600kReal Oviedo
2023-06-14€700kReal Oviedo
2023-10-13€1MReal Oviedo
2023-12-20€1.5MReal Oviedo
2024-06-24€1.8MReal Oviedo
2024-10-11€3MCA Osasuna
2024-12-27€3MCA Osasuna
2025-06-09€4MCA Osasuna
2025-12-12€4.5MCA Osasuna
2026-03-16€4MCA Osasuna
2026-06-05€3.5MCA Osasuna

Audit context group-level, not about this player

Audit group
UEFA
Population gap, Model A
+0.093 95% CI +0.063 to +0.124
This player, market vs held-out A
+0.091

The group comes from first-listed citizenship and is never a model input. Across the population, non-UEFA players' market values sit about 10% above Model A's held-out estimates, relative to UEFA players in the same leagues. One player's residual says nothing about that pattern (typical miss ×1.50), and none of it is evidence of discrimination: the target may itself be biased. Open the Fairness Audit

In context observed value among comparable players in this build

All players in the Terminal →

LaLiga509 players · median €4M

Valued above 47% of the 509 LaLiga players.

€100k€1M€10M€100M€3.5MSee them in the Explorer →

Defenders, all leagues2,065 players · median €2M

Valued above 63% of the 2,065 defenders.

€20k€200k€2M€20M€3.5MSee them in the Explorer →

Where Bretones appears

Watchlists and the comparison tray are kept in this browser only.

Near this valuation closest observed values: same league, then same position

Counts and ranks of observed Transfermarkt values only; model errors are never ranked here. Full player export: Every player in the modelling population (D-011).