FairValue

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Dylan

Mertens

AMNetherlands · SC Telstar

№ 322616Emerging €462k −0.84

Player dossierEredivisie

DylanMertens

AMAttacking MidfieldMidfield

Club
SC Telstar
League
Eredivisie
Nationality
Netherlands
Age
30
Height
187 cm
Foot
Right
Valued
28 May 2026

Reading the valuation

The market values Mertens at €200k. Model A, which never saw Mertens during training, estimates €462k: the market value is 57% below that estimate.

That is a factor of ×2.31. 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 €652k, 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.

▼ −0.84A €462k▼ −1.18B €652k
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
57
Minutes
2,175
Goals
0
Assists
0
Started
23/57
Min / app
38
Cards
8Y 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 Mertens…

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 €200k

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €200kModel A €462k

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

Dylan Mertens's percentiles among midfielders: Goals per 90 10th, Assists per 90 8th, Minutes, two years 41st, Starts 12th, Minutes, last 365 days 14th, European club minutes 30th10thGoals8thAssists41stMinutes12thStarts14thRecent30thEurope

Dashed ring: the midfielder median (50th percentile)

Minutes, two years

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

2,175 this player2,607 midfielder median41st percentile

451peer deciles · median line · this player ●9,624

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
Aug 2014
Peak
€600k
Jun 2024
Model target
€200k
May 2026
Valuations
25
5 club changes
May 2026€200kSC TelstarValuation the model is trained to reproduce

May 2026: €200k, SC Telstar. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2014-08-16€25kFC Volendam
2015-02-21€25kFC Volendam
2015-07-01€25kFC Volendam
2016-02-05€75kFC Volendam
2016-07-01€100kFC Volendam
2017-02-02€75kFC Volendam
2017-06-21€50kFC Volendam
2018-03-01€75kFC Volendam
2018-06-29€75kFC Volendam
2019-01-21€100kSC Telstar
2019-06-20€50kSC Telstar
2020-12-21€100kTsarsko Selo (-2022)
2021-06-17€300kTsarsko Selo (-2022)
2021-12-08€350kBotev Plovdiv
2022-05-31€400kBotev Plovdiv
2022-09-07€500kBotev Plovdiv
2022-11-28€500kBotev Plovdiv
2023-06-05€500kBotev Plovdiv
2023-12-20€500kBotev Plovdiv
2024-06-03€600kBotev Plovdiv
2024-12-12€600kFakel Voronezh
2025-06-04€500kFakel Voronezh
2025-12-02€400kSC Telstar
2026-03-11€300kSC Telstar
2026-05-28€200kSC Telstar

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
−0.837

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 3% of the 425 Eredivisie players.

€75k€500k€3M€20M€200kSee them in the Explorer →

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

Valued above 3% of the 1,687 midfielders.

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

Where Mertens 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).