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…

Portrait of Idrissa Gueye

Idrissa

Gueye

DMSenegal · Everton FC

№ 126665Emerging €1.2M −0.92

Image: FootyLogos

Player dossierPremier League

IdrissaGueye

DMDefensive MidfieldMidfield

Club
Everton FC
League
Premier League
Nationality
Senegal
Age
36
Height
174 cm
Foot
Right
Valued
3 Jun 2026

Reading the valuation

The market values Gueye at €500k. Model A, which never saw Gueye during training, estimates €1.2M: the market value is 60% below that estimate.

That is a factor of ×2.50. 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 €243k, 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.

▼ −0.92A €1.2M▲ +0.72B €243k
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
65
Minutes
5,369
Goals
2
Assists
6
Started
62/65
Min / app
83
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 Gueye…

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 €500k

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €500kModel A €1.2M

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

Idrissa Gueye's percentiles among midfielders: Goals per 90 26th, Assists per 90 53rd, Minutes, two years 90th, Starts 93rd, Minutes, last 365 days 68th, European club minutes 30th26thGoals53rdAssists90thMinutes93rdStarts68thRecent30thEurope

Dashed ring: the midfielder median (50th percentile)

Starts

Share of appearances started rather than entered from the bench.

95% this player69% midfielder median93rd percentile

7%peer deciles · median line · this player ●100%

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
€150k
Jul 2010
Peak
€30M
Sept 2019
Model target
€500k
Jun 2026
Valuations
39
4 club changes
Jun 2026€500kEverton FCValuation the model is trained to reproduce

Jun 2026: €500k, Everton FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2010-07-16€150kLOSC Lille
2010-12-28€500kLOSC Lille
2011-05-24€650kLOSC Lille
2011-12-24€1.8MLOSC Lille
2012-05-23€2.5MLOSC Lille
2013-01-07€3MLOSC Lille
2013-05-30€4MLOSC Lille
2014-01-14€4.5MLOSC Lille
2014-02-05€5MLOSC Lille
2014-08-07€5.5MLOSC Lille
2015-01-14€6MLOSC Lille
2015-06-06€7.5MLOSC Lille
2015-10-14€9MAston Villa
2016-02-09€9MAston Villa
2016-10-24€11MEverton FC
2017-02-20€12MEverton FC
2017-06-28€18MEverton FC
2018-01-02€18MEverton FC
2018-05-28€20MEverton FC
2018-12-19€20MEverton FC
2019-06-13€25MEverton FC
2019-09-27€30MParis Saint-Germain
2019-12-19€30MParis Saint-Germain
2020-04-08€24MParis Saint-Germain
2020-10-15€24MParis Saint-Germain
2021-01-07€18MParis Saint-Germain
2021-06-04€15MParis Saint-Germain
2021-12-16€13MParis Saint-Germain
2022-05-30€12MParis Saint-Germain
2022-09-15€10MEverton FC
2022-11-03€8MEverton FC
2023-06-20€5MEverton FC
2023-12-19€4MEverton FC
2024-05-27€3MEverton FC
2024-10-01€2MEverton FC
2024-12-16€2MEverton FC
2025-05-30€1.5MEverton FC
2025-12-09€1MEverton FC
2026-06-03€500kEverton FC

Audit context group-level, not about this player

Audit group
non-UEFA
Population gap, Model A
+0.093 95% CI +0.063 to +0.124
This player, market vs held-out A
−0.916

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 →

Premier League555 players · median €18M

Valued above 3% of the 555 Premier League players.

€150k€1M€7.5M€50M€500kSee them in the Explorer →

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

Valued above 16% of the 1,687 midfielders.

€20k€200k€2M€20M€500kSee them in the Explorer →

Where Gueye 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).