FairValue

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  • EnvironmentOverviewWhat FairValue measures, what it found, where to go next.
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Portrait of John Stones

John

Stones

CBEngland · Manchester City

№ 186590Elite €6M +0.69

Close-up

Image: FootyLogos

Player dossierPremier League

JohnStones

CBCentre-BackDefender

Club
Manchester City
League
Premier League
Nationality
England
Age
32
Height
188 cm
Foot
Right
Valued
3 Jun 2026

Reading the valuation

The market values Stones at €12M. Model A, which never saw Stones during training, estimates €6M: the market value is 100% above that estimate.

That is a factor of ×2.00. 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 €3.5M, 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.

▲ +0.69A €6M▲ +1.23B €3.5M
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
36
Minutes
2,098
Goals
3
Assists
2
Started
24/36
Min / app
58
Cards
2Y 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 Stones…

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 €12M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €12MModel A €6M

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

John Stones's percentiles among defenders: Goals per 90 93rd, Assists per 90 73rd, Minutes, two years 36th, Starts 23rd, Minutes, last 365 days 32nd, European club minutes 97th93rdGoals73rdAssists36thMinutes23rdStarts32ndRecent97thEurope

Dashed ring: the defender median (50th percentile)

European club minutes

Share of minutes played in UEFA club competitions.

34% this player0% defender median97th percentile

0%peer deciles · median line · this player ●85%

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
€50k
Aug 2011
Peak
€60M
Dec 2018
Model target
€12M
Jun 2026
Valuations
42
3 club changes
Jun 2026€12MManchester CityValuation the model is trained to reproduce

Jun 2026: €12M, Manchester City. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2011-08-15€50kBarnsley FC U18
2012-12-10€100kBarnsley FC
2013-02-03€3.5MEverton FC
2013-07-02€3.5MEverton FC
2014-01-15€4MEverton FC
2014-08-12€7MEverton FC
2015-02-12€10MEverton FC
2015-07-01€13MEverton FC
2015-10-14€25MEverton FC
2016-02-09€30MEverton FC
2016-06-01€28MEverton FC
2016-08-01€28MEverton FC
2016-10-24€35MManchester City
2017-02-20€35MManchester City
2017-06-28€35MManchester City
2018-01-02€40MManchester City
2018-03-23€50MManchester City
2018-05-28€50MManchester City
2018-07-16€55MManchester City
2018-12-19€60MManchester City
2019-06-13€60MManchester City
2019-12-10€60MManchester City
2020-03-09€45MManchester City
2020-04-08€36MManchester City
2020-07-30€30MManchester City
2020-10-13€25MManchester City
2021-03-18€30MManchester City
2021-05-28€30MManchester City
2021-12-23€28MManchester City
2022-06-15€28MManchester City
2022-09-15€30MManchester City
2022-11-03€30MManchester City
2023-06-20€40MManchester City
2023-12-19€38MManchester City
2024-05-27€38MManchester City
2024-12-16€32MManchester City
2025-03-18€30MManchester City
2025-05-30€25MManchester City
2025-10-17€22MManchester City
2025-12-09€18MManchester City
2026-03-09€15MManchester City
2026-06-03€12MManchester City

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
+0.692

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 →

Premier League555 players · median €18M

Valued above 36% of the 555 Premier League players.

€150k€1M€7.5M€50M€12MSee them in the Explorer →

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

Valued above 84% of the 2,065 defenders.

€20k€200k€2M€20M€12MSee them in the Explorer →

Where Stones 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).