FairValue

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Portrait of Teun Koopmeiners

Teun

Koopmeiners

DMNetherlands · Juventus FC

№ 360518Elite €17.8M −0.24

Close-up

Image: FootyLogos

Player dossierSerie A

TeunKoopmeiners

DMDefensive MidfieldMidfield

Club
Juventus FC
League
Serie A
Nationality
Netherlands
Age
28
Height
185 cm
Foot
Left
Valued
29 May 2026

Reading the valuation

The market values Koopmeiners at €14M. Model A, which never saw Koopmeiners during training, estimates €17.8M: the market value is 21% below that estimate.

That is a factor of ×1.27. 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 €19.3M, 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.

▼ −0.24A €17.8M▼ −0.32B €19.3M
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
90
Minutes
5,760
Goals
7
Assists
4
Started
63/90
Min / app
64
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 Koopmeiners…

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 €14M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €14MModel A €17.8M

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

Teun Koopmeiners's percentiles among midfielders: Goals per 90 59th, Assists per 90 35th, Minutes, two years 93rd, Starts 51st, Minutes, last 365 days 88th, European club minutes 93rd59thGoals35thAssists93rdMinutes51stStarts88thRecent93rdEurope

Dashed ring: the midfielder median (50th percentile)

European club minutes

Share of minutes played in UEFA club competitions.

27% this player0% midfielder median93rd 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
€350k
Jul 2017
Peak
€55M
Oct 2024
Model target
€14M
May 2026
Valuations
32
2 club changes
May 2026€14MJuventus FCValuation the model is trained to reproduce

May 2026: €14M, Juventus FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2017-07-01€350kAZ Alkmaar
2017-10-26€600kAZ Alkmaar
2018-01-17€1.3MAZ Alkmaar
2018-03-27€2MAZ Alkmaar
2018-06-12€3.5MAZ Alkmaar
2018-12-28€3.5MAZ Alkmaar
2019-03-13€5MAZ Alkmaar
2019-06-12€5MAZ Alkmaar
2019-09-19€7.5MAZ Alkmaar
2019-12-18€14MAZ Alkmaar
2020-03-12€16MAZ Alkmaar
2020-04-08€14.5MAZ Alkmaar
2020-10-14€14.5MAZ Alkmaar
2021-01-06€15MAZ Alkmaar
2021-03-06€17.5MAZ Alkmaar
2021-05-27€16.5MAZ Alkmaar
2021-12-28€18MAtalanta BC
2022-03-15€25MAtalanta BC
2022-06-07€25MAtalanta BC
2022-11-11€30MAtalanta BC
2023-06-15€30MAtalanta BC
2023-10-11€35MAtalanta BC
2023-12-20€40MAtalanta BC
2024-06-05€50MAtalanta BC
2024-10-18€55MJuventus FC
2024-12-18€50MJuventus FC
2025-03-25€40MJuventus FC
2025-06-17€35MJuventus FC
2025-10-07€30MJuventus FC
2025-12-23€28MJuventus FC
2026-03-24€20MJuventus FC
2026-05-29€14MJuventus FC

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
−0.238

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 →

Serie A507 players · median €5.5M

Valued above 73% of the 507 Serie A players.

€100k€750k€5M€30M€14MSee them in the Explorer →

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

Valued above 83% of the 1,687 midfielders.

€20k€200k€2M€20M€14MSee them in the Explorer →

Where Koopmeiners 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).