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…

Boli

Bolingoli

LBBelgium · Standard Liège

№ 168156Emerging €340k −0.53

Player dossierPro League

BoliBolingoli

LBLeft-BackDefender

Club
Standard Liège
League
Pro League
Nationality
Belgium
Age
30
Height
181 cm
Foot
Left
Valued
4 Jun 2026

Reading the valuation

The market values Bolingoli at €200k. Model A, which never saw Bolingoli during training, estimates €340k: the market value is 41% below that estimate.

That is a factor of ×1.70. 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 €387k, 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.

▼ −0.53A €340k▼ −0.66B €387k
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
584
Goals
0
Assists
0
Started
4/15
Min / app
39
Cards
3Y 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 Bolingoli…

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 €200k

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €200kModel A €340k

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

Boli Bolingoli's percentiles among defenders: Goals per 90 18th, Assists per 90 17th, Minutes, two years 3rd, Starts 1st, Minutes, last 365 days 4th, European club minutes 30th18thGoals17thAssists3rdMinutes1stStarts4thRecent30thEurope

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
€300k
Aug 2013
Peak
€3.5M
Dec 2018
Model target
€200k
Jun 2026
Valuations
32
7 club changes
Jun 2026€200kStandard LiègeValuation the model is trained to reproduce

Jun 2026: €200k, Standard Liège. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2013-08-12€300kClub Brugge KV
2013-10-08€600kClub Brugge KV
2014-02-10€500kClub Brugge KV
2014-06-28€500kClub Brugge KV
2015-01-07€500kClub Brugge KV
2015-03-24€1MClub Brugge KV
2015-06-24€1.5MClub Brugge KV
2016-02-07€1.5MClub Brugge KV
2016-07-15€1.2MClub Brugge KV
2017-01-21€900kSint-Truidense VV
2017-06-06€900kSint-Truidense VV
2018-01-02€1.3MRapid Vienna
2018-06-14€3MRapid Vienna
2018-12-19€3.5MRapid Vienna
2019-06-03€3.5MRapid Vienna
2020-02-05€3MCeltic FC
2020-04-08€2.4MCeltic FC
2020-07-21€2.8MCeltic FC
2020-12-23€2.8MBasaksehir FK
2021-03-16€2.4MBasaksehir FK
2021-05-21€2.2MBasaksehir FK
2021-12-31€1.5MCeltic FC
2022-06-27€1MCeltic FC
2022-11-04€900kKV Mechelen
2023-06-09€700kKV Mechelen
2023-10-23€500kKV Mechelen
2023-12-19€500kKV Mechelen
2024-06-04€500kKV Mechelen
2024-12-11€500kStandard Liège
2025-06-12€500kStandard Liège
2025-12-10€400kStandard Liège
2026-06-04€200kStandard Liège

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
−0.531

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 1% of the 350 Pro League players.

€100k€750k€5M€30M€200kSee them in the Explorer →

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

Valued above 5% of the 2,065 defenders.

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

Where Bolingoli 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).