FairValue

Checking model

Esc

  • EnvironmentOverviewWhat FairValue measures, what it found, where to go next.
  • EnvironmentTerminalExplore, compare and track players; market, league and model views.
  • EnvironmentStoriesValuations, head-to-heads and research findings, told as stories.
  • TerminalPlayer ExplorerSearch, filter and sort the player export.
  • TerminalComparison StudioTwo to four players on one scale.
  • TerminalWatchlistsNamed collections, kept in this browser.
  • TerminalMarket LandscapeHow observed value is distributed, and where the model drifts.

↑ ↓ to move · Enter to open · Esc to closeLoading player index…

César

Azpilicueta

CBSpain · Sevilla FC

№ 57500Emerging €551k +0.60

Player dossierLaLiga

CésarAzpilicueta

CBCentre-BackDefender

Club
Sevilla FC
League
LaLiga
Nationality
Spain
Age
36
Height
178 cm
Foot
Right
Valued
5 Jun 2026

Reading the valuation

The market values Azpilicueta at €1M. Model A, which never saw Azpilicueta during training, estimates €551k: the market value is 81% above that estimate.

That is a factor of ×1.81. Model A's typical held-out miss is ×1.50 either way, so this gap is larger than its usual error.

Without league and club, Model B estimates €488k, 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.

▲ +0.60A €551k▲ +0.72B €488k
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
37
Minutes
2,416
Goals
1
Assists
1
Started
31/37
Min / app
65
Cards
7Y 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 Azpilicueta…

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 €1M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €1MModel A €551k

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

César Azpilicueta's percentiles among defenders: Goals per 90 54th, Assists per 90 49th, Minutes, two years 42nd, Starts 53rd, Minutes, last 365 days 35th, European club minutes 66th54thGoals49thAssists42ndMinutes53rdStarts35thRecent66thEurope

Dashed ring: the defender median (50th percentile)

European club minutes

Share of minutes played in UEFA club competitions.

5% this player0% defender median66th percentile

0%peer deciles · median line · this player ●85%

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
€400k
Aug 2007
Peak
€40M
Mar 2018
Model target
€1M
Jun 2026
Valuations
45
4 club changes
Jun 2026€1MSevilla FCValuation the model is trained to reproduce

Jun 2026: €1M, Sevilla FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2007-08-28€400kCA Osasuna
2008-02-04€1.2MCA Osasuna
2008-07-22€2MCA Osasuna
2008-10-15€3.6MCA Osasuna
2009-01-21€3.6MCA Osasuna
2009-07-22€5MCA Osasuna
2009-12-02€6MCA Osasuna
2010-04-08€7MCA Osasuna
2011-05-24€6.5MOlympique Marseille
2011-12-24€6.5MOlympique Marseille
2012-05-23€7.5MOlympique Marseille
2012-09-09€9MChelsea FC
2013-01-28€14MChelsea FC
2013-07-02€18MChelsea FC
2014-01-15€18MChelsea FC
2014-08-12€20MChelsea FC
2015-02-12€21MChelsea FC
2015-07-01€23MChelsea FC
2016-02-09€20MChelsea FC
2016-06-01€20MChelsea FC
2016-08-01€20MChelsea FC
2017-02-20€25MChelsea FC
2017-06-28€30MChelsea FC
2018-01-02€35MChelsea FC
2018-03-23€40MChelsea FC
2018-05-28€40MChelsea FC
2018-12-19€40MChelsea FC
2019-06-13€35MChelsea FC
2019-12-10€30MChelsea FC
2020-04-08€24MChelsea FC
2020-10-13€20MChelsea FC
2020-12-17€17MChelsea FC
2021-03-18€17MChelsea FC
2021-05-31€13MChelsea FC
2021-12-23€11MChelsea FC
2022-06-15€9MChelsea FC
2022-11-03€8MChelsea FC
2023-06-20€5MChelsea FC
2023-12-22€4MAtlético de Madrid
2024-03-21€3MAtlético de Madrid
2024-06-07€2MAtlético de Madrid
2024-12-27€1.8MAtlético de Madrid
2025-06-09€1.5MAtlético de Madrid
2025-12-12€1.2MSevilla FC
2026-06-05€1MSevilla FC

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
+0.596

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 8% of the 509 LaLiga players.

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

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

Valued above 35% of the 2,065 defenders.

€20k€200k€2M€20M€1MSee them in the Explorer →

Where Azpilicueta 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).