Maxim
Dekker
CBNetherlands · AZ Alkmaar
Player dossierEredivisie
MaximDekker
CBCentre-BackDefender
- Club
- AZ Alkmaar
- League
- Eredivisie
- Nationality
- Netherlands
- Age
- 22
- Height
- 192 cm
- Foot
- Left
- Valued
- 28 May 2026
Reading the valuation
The market values Dekker at €650k. Model A, which never saw Dekker during training, estimates €1.3M: the market value is 49% below that estimate.
That is a factor of ×1.96. 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 €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.
- Apps
- 24
- Minutes
- 1,323
- Goals
- 0
- Assists
- 0
- Started
- 15/24
- Min / app
- 55
- Cards
- 2Y 1R
Club matches, two years to the valuation date
The Valuation Journey
What moves Model A
Asking the prediction API to explain Model A for Dekker…
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 €650k
Checking APIAsking 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
Dashed ring: the defender median (50th percentile)
European club minutes
Share of minutes played in UEFA club competitions.
26% this player0% defender median91st percentile
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
- €25k
- Oct 2021
- Peak
- €1.5M
- Nov 2022
- Model target
- €650k
- May 2026
- Valuations
- 12
- 1 club change
May 2026: €650k, AZ Alkmaar. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2021-10-12 | €25k | AZ Alkmaar U21 |
| 2022-01-12 | €100k | AZ Alkmaar U21 |
| 2022-06-23 | €400k | AZ Alkmaar U21 |
| 2022-09-14 | €700k | AZ Alkmaar |
| 2022-11-11 | €1.5M | AZ Alkmaar |
| 2023-06-23 | €1.5M | AZ Alkmaar |
| 2023-12-15 | €1M | AZ Alkmaar |
| 2024-05-31 | €800k | AZ Alkmaar |
| 2024-12-17 | €1M | AZ Alkmaar |
| 2025-05-28 | €1M | AZ Alkmaar |
| 2025-12-02 | €800k | AZ Alkmaar |
| 2026-05-28 | €650k | AZ Alkmaar |
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
- −0.674
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 32% of the 425 Eredivisie players.
See them in the Explorer →Defenders, all leagues2,065 players · median €2M
Valued above 25% of the 2,065 defenders.
See them in the Explorer →Where Dekker appears
Watchlists and the comparison tray are kept in this browser only.
Near this valuation closest observed values: same league, then same position
- ThomasDMPEC Zwolle · Eredivisie€650k
- Ould-ChikhRWFC Volendam · Eredivisie€650k
- MonteiroCMPEC Zwolle · Eredivisie€650k
- BehounekCBWillem II Tilburg · Eredivisie€650k
- VelkovCBVejle Boldklub · defenders€650k
- LissensCBRanders FC · defenders€650k
- CappelleLBZulte Waregem · defenders€650k
- GabrielRBFC Midtjylland · defenders€650k
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).