FairValue

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

Leoni

CMBelgium · Stade Reims

№ 418071Established €4M −0.30

Player dossierLigue 1

ThéoLeoni

CMCentral MidfieldMidfield

Club
Stade Reims
League
Ligue 1
Nationality
Belgium
Age
25
Height
174 cm
Foot
Left
Valued
11 Dec 2025

Reading the valuation

The market values Leoni at €3M. Model A, which never saw Leoni during training, estimates €4M: the market value is 26% below that estimate.

That is a factor of ×1.35. 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 €3.3M, 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.

▼ −0.30A €4M▼ −0.09B €3.3M
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
45
Minutes
2,831
Goals
5
Assists
2
Started
31/45
Min / app
63
Cards
5Y 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 Leoni…

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 €4M

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 1,687 midfielders

Théo Leoni's percentiles among midfielders: Goals per 90 74th, Assists per 90 35th, Minutes, two years 54th, Starts 49th, Minutes, last 365 days 21st, European club minutes 90th74thGoals35thAssists54thMinutes49thStarts21stRecent90thEurope

Dashed ring: the midfielder median (50th percentile)

European club minutes

Share of minutes played in UEFA club competitions.

24% this player0% midfielder median90th 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
€100k
Mar 2021
Peak
€5M
Mar 2024
Model target
€3M
Dec 2025
Valuations
13
3 club changes
Dec 2025€3MStade ReimsValuation the model is trained to reproduce

Dec 2025: €3M, Stade Reims. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2021-03-17€100kRSC Anderlecht U21
2021-06-07€100kRSC Anderlecht U21
2022-10-05€350kRSCA Futures
2022-12-22€800kRSCA Futures
2023-05-30€800kRSCA Futures
2023-10-23€4MRSC Anderlecht
2023-12-19€4MRSC Anderlecht
2024-03-22€5MRSC Anderlecht
2024-06-04€5MRSC Anderlecht
2024-12-11€5MRSC Anderlecht
2025-03-26€4MRSC Anderlecht
2025-06-12€3MRSC Anderlecht
2025-12-11€3MStade 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
−0.297

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 30% of the 423 Ligue 1 players.

€100k€750k€5M€30M€3MSee them in the Explorer →

Midfielders, all leagues1,687 players · median €2M

Valued above 56% of the 1,687 midfielders.

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

Where Leoni 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).