FairValue

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

Arthur

CBEngland · Celtic FC

№ 1144158Emerging €787k −2.06

Player dossierPremiership

BenjaminArthur

CBCentre-BackDefender

Club
Celtic FC
League
Premiership
Nationality
England
Age
20
Height
192 cm
Foot
Right
Valued
20 May 2026

Reading the valuation

The market values Arthur at €100k. Model A, which never saw Arthur during training, estimates €787k: the market value is 87% below that estimate.

That is a factor of ×7.87. 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 €1M, 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.

▼ −2.06A €787k▼ −2.32B €1M
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
9
Minutes
607
Goals
0
Assists
0
Started
7/9
Min / app
67
Cards
0Y 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 Arthur…

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 €100k

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €100kModel A €787k

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

Benjamin Arthur's percentiles among defenders: Goals per 90 18th, Assists per 90 17th, Minutes, two years 3rd, Starts 40th, Minutes, last 365 days 15th, European club minutes 30th18thGoals17thAssists3rdMinutes40thStarts15thRecent30thEurope

Dashed ring: the defender median (50th percentile)

Starts

Share of appearances started rather than entered from the bench.

78% this player83% defender median40th 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
€100k
Mar 2026
Peak
€100k
Mar 2026
Model target
€100k
May 2026
Valuations
2
0 club changes
May 2026€100kCeltic FCValuation the model is trained to reproduce

May 2026: €100k, Celtic FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2026-03-05€100kCeltic FC
2026-05-20€100kCeltic 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
−2.064

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 →

Premiership311 players · median €400k

Valued above 7% of the 311 Premiership players.

€20k€150k€1M€7.5M€100kSee them in the Explorer →

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

Valued above 1% of the 2,065 defenders.

€20k€200k€2M€20M€100kSee them in the Explorer →

Where Arthur 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).