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…

Maxime

Busi

RBBelgium · Stade Reims

№ 570817Emerging €1.3M −0.51

Player dossierLigue 1

MaximeBusi

RBRight-BackDefender

Club
Stade Reims
League
Ligue 1
Nationality
Belgium
Age
26
Height
182 cm
Foot
Right
Valued
11 Dec 2025

Reading the valuation

The market values Busi at €800k. Model A, which never saw Busi during training, estimates €1.3M: the market value is 40% below that estimate.

That is a factor of ×1.66. 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 €579k, closer to the market here, although it is usually further off (typical miss ×2.07).

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

▼ −0.51A €1.3M▲ +0.32B €579k
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
15
Minutes
902
Goals
0
Assists
0
Started
9/15
Min / app
60
Cards
0Y 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 Busi…

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 €800k

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €800kModel A €1.3M

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

Maxime Busi's percentiles among defenders: Goals per 90 18th, Assists per 90 17th, Minutes, two years 10th, Starts 15th, Minutes, last 365 days 25th, European club minutes 30th18thGoals17thAssists10thMinutes15thStarts25thRecent30thEurope

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
€50k
Aug 2018
Peak
€5M
Oct 2020
Model target
€800k
Dec 2025
Valuations
21
4 club changes
Dec 2025€800kStade ReimsValuation the model is trained to reproduce

Dec 2025: €800k, Stade Reims. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2018-08-01€50kRoyal Charleroi SC
2018-12-27€100kRoyal Charleroi SC
2019-03-04€250kRoyal Charleroi SC
2019-06-10€300kRoyal Charleroi SC
2019-12-13€850kRoyal Charleroi SC
2020-02-11€1.5MRoyal Charleroi SC
2020-04-08€1.3MRoyal Charleroi SC
2020-08-06€2.5MRoyal Charleroi SC
2020-10-29€5MParma Calcio 1913
2020-12-29€5MParma Calcio 1913
2021-06-03€4.5MParma Calcio 1913
2021-12-29€3MParma Calcio 1913
2022-05-30€3.5MStade Reims
2022-11-02€3MStade Reims
2023-06-27€2.5MStade Reims
2023-12-18€2MStade Reims
2024-06-03€1.5MStade Reims
2024-12-10€1.2MStade Reims
2025-05-28€1MNAC Breda
2025-10-13€800kStade Reims
2025-12-11€800kStade Reims

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
−0.507

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 →

Ligue 1423 players · median €5M

Valued above 7% of the 423 Ligue 1 players.

€100k€750k€5M€30M€800kSee them in the Explorer →

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

Valued above 29% of the 2,065 defenders.

€20k€200k€2M€20M€800kSee them in the Explorer →

Where Busi 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).