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Gideon

Mensah

LBGhana · AJ Auxerre

№ 397171Established €3.6M +0.12

Player dossierLigue 1

GideonMensah

LBLeft-BackDefender

Club
AJ Auxerre
League
Ligue 1
Nationality
Ghana
Age
27
Height
178 cm
Foot
Left
Valued
1 Jun 2026

Reading the valuation

The market values Mensah at €4M. Model A, which never saw Mensah during training, estimates €3.6M: the market value is 12% above that estimate.

That is a factor of ×1.12. 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 €4.1M, 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.

▲ +0.12A €3.6M▼ −0.03B €4.1M
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
59
Minutes
4,618
Goals
0
Assists
2
Started
52/59
Min / app
78
Cards
10Y 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 Mensah…

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 €4M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €4MModel A €3.6M

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

Gideon Mensah's percentiles among defenders: Goals per 90 18th, Assists per 90 50th, Minutes, two years 78th, Starts 64th, Minutes, last 365 days 72nd, European club minutes 30th18thGoals50thAssists78thMinutes64thStarts72ndRecent30thEurope

Dashed ring: the defender median (50th percentile)

Minutes, two years

Total club minutes in the two-year window: how much the player was used.

4,618 this player2,860 defender median78th percentile

451peer deciles · median line · this player ●9,111

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
Jul 2016
Peak
€4M
Jun 2025
Model target
€4M
Jun 2026
Valuations
24
5 club changes
Jun 2026€4MAJ AuxerreValuation the model is trained to reproduce

Jun 2026: €4M, AJ Auxerre. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2016-07-22€100kFC Liefering
2016-12-03€175kFC Liefering
2017-05-27€300kFC Liefering
2017-12-13€300kFC Liefering
2018-06-13€400kFC Liefering
2018-12-01€400kFC Liefering
2019-04-15€600kSK Sturm Graz
2019-06-03€900kSK Sturm Graz
2019-12-13€1.5MZulte Waregem
2020-03-30€3MZulte Waregem
2020-04-08€2.7MZulte Waregem
2020-10-22€2.5MVitória Guimarães SC
2021-01-28€2.5MVitória Guimarães SC
2021-05-21€2.5MVitória Guimarães SC
2021-12-16€2.2MFC Girondins Bordeaux
2022-05-30€2.5MFC Girondins Bordeaux
2022-11-02€2MAJ Auxerre
2023-06-27€2.5MAJ Auxerre
2023-12-13€2.5MAJ Auxerre
2024-06-11€2.5MAJ Auxerre
2024-12-10€3.5MAJ Auxerre
2025-06-03€4MAJ Auxerre
2025-12-15€3.5MAJ Auxerre
2026-06-01€4MAJ Auxerre

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
+0.117

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 37% of the 423 Ligue 1 players.

€100k€750k€5M€30M€4MSee them in the Explorer →

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

Valued above 65% of the 2,065 defenders.

€20k€200k€2M€20M€4MSee them in the Explorer →

Where Mensah 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).