FairValue

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  • 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.

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Portrait of Willy Kambwala

Willy

Kambwala

CBFrance · Villarreal CF

№ 780630Established €4.7M −0.44

Close-up

Image: FootyLogos

Player dossierLaLiga

WillyKambwala

CBCentre-BackDefender

Club
Villarreal CF
League
LaLiga
Nationality
France
Age
21
Height
192 cm
Foot
Right
Valued
5 Jun 2026

Reading the valuation

The market values Kambwala at €3M. Model A, which never saw Kambwala during training, estimates €4.7M: the market value is 36% below that estimate.

That is a factor of ×1.55. 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 €1.4M, 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.

▼ −0.44A €4.7M▲ +0.77B €1.4M
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
23
Minutes
1,367
Goals
0
Assists
0
Started
15/23
Min / app
59
Cards
1Y 1R

Club matches, two years to the valuation date

The Valuation Journey

What moves Model A

Asking the prediction API to explain Model A for Kambwala…

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 €3M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €3MModel A €4.7M

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

Willy Kambwala's percentiles among defenders: Goals per 90 18th, Assists per 90 17th, Minutes, two years 20th, Starts 21st, Minutes, last 365 days 3rd, European club minutes 30th18thGoals17thAssists20thMinutes21stStarts3rdRecent30thEurope

Dashed ring: the defender median (50th percentile)

European club minutes

Share of minutes played in UEFA club competitions.

0% this player0% defender median30th 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
€2M
Dec 2023
Peak
€5M
Mar 2024
Model target
€3M
Jun 2026
Valuations
7
2 club changes
Jun 2026€3MVillarreal CFValuation the model is trained to reproduce

Jun 2026: €3M, Villarreal CF. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2023-12-19€2MManchester United U21
2024-03-14€5MManchester United
2024-05-27€5MManchester United
2024-12-27€4MVillarreal CF
2025-06-09€4MVillarreal CF
2025-12-12€4MVillarreal CF
2026-06-05€3MVillarreal CF

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
−0.441

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 40% of the 509 LaLiga players.

€100k€1M€10M€100M€3MSee them in the Explorer →

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

Valued above 59% of the 2,065 defenders.

€20k€200k€2M€20M€3MSee them in the Explorer →

Where Kambwala 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).