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…

Louis

Patris

RBBelgium · Union Saint-Gilloise

№ 502247Established €2.5M −0.02

Player dossierPro League

LouisPatris

RBRight-BackDefender

Club
Union Saint-Gilloise
League
Pro League
Nationality
Belgium
Age
24
Height
187 cm
Foot
Right
Valued
4 Jun 2026

Reading the valuation

The market values Patris at €2.5M. Model A, which never saw Patris during training, estimates €2.5M: the market value is 2% below that estimate.

That is a factor of ×1.02. 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 €5.5M, 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.

▼ −0.02A €2.5M▼ −0.79B €5.5M
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
63
Minutes
3,261
Goals
0
Assists
8
Started
33/63
Min / app
52
Cards
9Y 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 Patris…

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 €2.5M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €2.5MModel A €2.5M

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

Louis Patris's percentiles among defenders: Goals per 90 18th, Assists per 90 97th, Minutes, two years 58th, Starts 9th, Minutes, last 365 days 47th, European club minutes 65th18thGoals97thAssists58thMinutes9thStarts47thRecent65thEurope

Dashed ring: the defender median (50th percentile)

Assists per 90

Club assists per 90 minutes in the same window.

0.22 this player0.04 defender median97th percentile

0.00peer deciles · median line · this player ●0.58

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
Mar 2021
Peak
€3.3M
Oct 2025
Model target
€2.5M
Jun 2026
Valuations
15
3 club changes
Jun 2026€2.5MUnion Saint-GilloiseValuation the model is trained to reproduce

Jun 2026: €2.5M, Union Saint-Gilloise. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2021-03-17€400kOud-Heverlee Leuven
2021-06-07€400kOud-Heverlee Leuven
2021-10-06€300kOud-Heverlee Leuven
2022-01-06€200kOud-Heverlee Leuven
2022-04-12€400kOud-Heverlee Leuven
2022-09-07€1MOud-Heverlee Leuven
2022-11-04€2MOud-Heverlee Leuven
2023-06-09€3MOud-Heverlee Leuven
2023-12-19€2.5MRSC Anderlecht
2024-06-04€2MRSC Anderlecht
2024-12-11€2MSint-Truidense VV
2025-06-12€2MSint-Truidense VV
2025-10-01€3.3MUnion Saint-Gilloise
2025-12-10€3MUnion Saint-Gilloise
2026-06-04€2.5MUnion Saint-Gilloise

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
−0.018

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 →

Pro League350 players · median €1.8M

Valued above 60% of the 350 Pro League players.

€100k€750k€5M€30M€2.5MSee them in the Explorer →

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

Valued above 54% of the 2,065 defenders.

€20k€200k€2M€20M€2.5MSee them in the Explorer →

Where Patris 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).