FairValue

Checking model

Esc

  • EnvironmentOverviewWhat FairValue measures, what it found, where to go next.
  • EnvironmentTerminalExplore, compare and track players; market, league and model views.
  • EnvironmentStoriesValuations, head-to-heads and research findings, told as stories.
  • TerminalPlayer ExplorerSearch, filter and sort the player export.
  • TerminalComparison StudioTwo to four players on one scale.
  • TerminalWatchlistsNamed collections, kept in this browser.
  • TerminalMarket LandscapeHow observed value is distributed, and where the model drifts.

↑ ↓ to move · Enter to open · Esc to closeLoading player index…

Guus

Offerhaus

CBNetherlands · SC Telstar

№ 590777Emerging €1.3M −0.50

Player dossierEredivisie

GuusOfferhaus

CBCentre-BackDefender

Club
SC Telstar
League
Eredivisie
Nationality
Netherlands
Age
25
Height
188 cm
Foot
Right
Valued
28 May 2026

Reading the valuation

The market values Offerhaus at €800k. Model A, which never saw Offerhaus during training, estimates €1.3M: the market value is 39% below that estimate.

That is a factor of ×1.65. 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 €4.6M, 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.

▼ −0.50A €1.3M▼ −1.75B €4.6M
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
3,420
Goals
3
Assists
3
Started
38/38
Min / app
90
Cards
7Y 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 Offerhaus…

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 €800k

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €800kModel A €1.3M

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

Guus Offerhaus's percentiles among defenders: Goals per 90 79th, Assists per 90 71st, Minutes, two years 61st, Starts 97th, Minutes, last 365 days 95th, European club minutes 30th79thGoals71stAssists61stMinutes97thStarts95thRecent30thEurope

Dashed ring: the defender median (50th percentile)

Starts

Share of appearances started rather than entered from the bench.

100% this player83% defender median97th percentile

18%peer deciles · median line · this player ●100%

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
Oct 2024
Peak
€800k
May 2026
Model target
€800k
May 2026
Valuations
5
0 club changes
May 2026€800kSC TelstarValuation the model is trained to reproduce

May 2026: €800k, SC Telstar. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2024-10-09€250kSC Telstar
2024-12-10€325kSC Telstar
2025-06-09€500kSC Telstar
2025-12-02€600kSC Telstar
2026-05-28€800kSC 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
−0.502

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 40% of the 425 Eredivisie players.

€75k€500k€3M€20M€800kSee them in the Explorer →

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

Valued above 29% of the 2,065 defenders.

€20k€200k€2M€20M€800kSee them in the Explorer →

Where Offerhaus 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).