FairValue

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

Janse

CBNetherlands · FC Groningen

№ 765743Established €5.5M +0.18

Player dossierEredivisie

DiesJanse

CBCentre-BackDefender

Club
FC Groningen
League
Eredivisie
Nationality
Netherlands
Age
20
Height
196 cm
Foot
Left
Valued
28 May 2026

Reading the valuation

The market values Janse at €6.5M. Model A, which never saw Janse during training, estimates €5.5M: the market value is 19% above that estimate.

That is a factor of ×1.19. 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 €16.6M, 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.

▲ +0.18A €5.5M▼ −0.94B €16.6M
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
38
Minutes
3,221
Goals
2
Assists
2
Started
35/38
Min / app
85
Cards
6Y 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 Janse…

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 €6.5M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €6.5MModel A €5.5M

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

Dies Janse's percentiles among defenders: Goals per 90 68th, Assists per 90 60th, Minutes, two years 57th, Starts 76th, Minutes, last 365 days 84th, European club minutes 63rd68thGoals60thAssists57thMinutes76thStarts84thRecent63rdEurope

Dashed ring: the defender median (50th percentile)

Minutes, last 365 days

Club minutes in the final year of the window: recent involvement, or the absence of it.

2,814 this player1,687 defender median84th percentile

0peer deciles · median line · this player ●4,941

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
€250k
Jan 2024
Peak
€6.5M
May 2026
Model target
€6.5M
May 2026
Valuations
9
2 club changes
May 2026€6.5MFC GroningenValuation the model is trained to reproduce

May 2026: €6.5M, FC Groningen. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2024-01-08€250kAjax U18
2024-06-10€300kAjax U18
2024-10-14€800kAjax Amsterdam U21
2024-12-17€800kAjax Amsterdam U21
2025-06-09€900kAjax Amsterdam U21
2025-10-02€2MFC Groningen
2025-12-02€3.5MFC Groningen
2026-03-11€4.5MFC Groningen
2026-05-28€6.5MFC Groningen

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
+0.176

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 →

Eredivisie425 players · median €1M

Valued above 86% of the 425 Eredivisie players.

€75k€500k€3M€20M€6.5MSee them in the Explorer →

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

Valued above 76% of the 2,065 defenders.

€20k€200k€2M€20M€6.5MSee them in the Explorer →

Where Janse 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).