FairValue

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

John

LBWales · St. Mirren FC

№ 238585Emerging €170k −0.13

Player dossierPremiership

DeclanJohn

LBLeft-BackDefender

Club
St. Mirren FC
League
Premiership
Nationality
Wales
Age
30
Height
178 cm
Foot
Left
Valued
20 May 2026

Reading the valuation

The market values John at €150k. Model A, which never saw John during training, estimates €170k: the market value is 12% below that estimate.

That is a factor of ×1.14. 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 €718k, 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.

▼ −0.13A €170k▼ −1.57B €718k
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
48
Minutes
3,756
Goals
3
Assists
6
Started
42/48
Min / app
78
Cards
1Y 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 John…

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 €150k

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €150kModel A €170k

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

Declan John's percentiles among defenders: Goals per 90 76th, Assists per 90 87th, Minutes, two years 66th, Starts 62nd, Minutes, last 365 days 81st, European club minutes 30th76thGoals87thAssists66thMinutes62ndStarts81stRecent30thEurope

Dashed ring: the defender median (50th percentile)

Assists per 90

Club assists per 90 minutes in the same window.

0.14 this player0.04 defender median87th percentile

0.00peer deciles · median line · this player ●0.58

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
Jan 2014
Peak
€1M
Sept 2018
Model target
€150k
May 2026
Valuations
23
9 club changes
May 2026€150kSt. Mirren FCValuation the model is trained to reproduce

May 2026: €150k, St. Mirren FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2014-01-15€250kCardiff City
2014-01-20€500kCardiff City
2015-02-24€500kCardiff City
2015-09-24€500kCardiff City
2016-09-01€500kCardiff City
2017-02-27€350kCardiff City
2018-03-04€650kRangers FC
2018-08-08€700kRangers FC
2018-09-24€1MSwansea City
2019-06-28€800kSwansea City
2020-04-08€650kSunderland AFC
2020-10-15€400kSwansea City
2021-06-30€300kSwansea City
2022-07-29€450kBolton Wanderers
2023-04-05€450kBolton Wanderers
2023-06-09€450kBolton Wanderers
2023-12-29€450kSalford City
2024-06-28€300kBolton Wanderers
2024-10-16€250kWithout Club
2024-12-03€250kSt. Mirren FC
2025-06-17€250kSt. Mirren FC
2025-12-10€250kSt. Mirren FC
2026-05-20€150kSt. Mirren 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
−0.128

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 18% of the 311 Premiership players.

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

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

Valued above 3% of the 2,065 defenders.

€20k€200k€2M€20M€150kSee them in the Explorer →

Where John 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).