FairValue

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Portrait of Aarón Martín

Aarón

Martín

LBSpain · Genoa CFC

№ 251878Established €3.7M +0.29

Close-up

Image: FootyLogos

Player dossierSerie A

AarónMartín

LBLeft-BackDefender

Club
Genoa CFC
League
Serie A
Nationality
Spain
Age
29
Height
178 cm
Foot
Left
Valued
29 May 2026

Reading the valuation

The market values Martín at €5M. Model A, which never saw Martín during training, estimates €3.7M: the market value is 33% above that estimate.

That is a factor of ×1.33. 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 €5.8M, closer to the market here, although it is usually further off (typical miss ×2.07).

A gap describes the model's arithmetic for this player's inputs, not what the player is worth.

▲ +0.29A €3.7M▼ −0.15B €5.8M
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
73
Minutes
5,574
Goals
1
Assists
14
Started
65/73
Min / app
76
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 Martín…

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 €5M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €5MModel A €3.7M

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

Aarón Martín's percentiles among defenders: Goals per 90 37th, Assists per 90 97th, Minutes, two years 89th, Starts 66th, Minutes, last 365 days 72nd, European club minutes 30th37thGoals97thAssists89thMinutes66thStarts72ndRecent30thEurope

Dashed ring: the defender median (50th percentile)

Assists per 90

Club assists per 90 minutes in the same window.

0.23 this player0.04 defender median97th 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
€300k
Aug 2016
Peak
€20M
Mar 2018
Model target
€5M
May 2026
Valuations
30
5 club changes
May 2026€5MGenoa CFCValuation the model is trained to reproduce

May 2026: €5M, Genoa CFC. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2016-08-01€300kRCD Espanyol B
2016-10-27€500kRCD Espanyol Barcelona
2017-01-24€3MRCD Espanyol Barcelona
2017-03-29€6MRCD Espanyol Barcelona
2017-06-05€10MRCD Espanyol Barcelona
2018-01-01€15MRCD Espanyol Barcelona
2018-03-22€20MRCD Espanyol Barcelona
2018-05-30€12MRCD Espanyol Barcelona
2018-08-22€10M1.FSV Mainz 05
2018-12-18€12M1.FSV Mainz 05
2019-03-06€16M1.FSV Mainz 05
2019-06-05€20M1.FSV Mainz 05
2019-12-17€16M1.FSV Mainz 05
2020-03-11€13M1.FSV Mainz 05
2020-04-08€10.5M1.FSV Mainz 05
2020-09-16€7M1.FSV Mainz 05
2020-11-26€4.5M1.FSV Mainz 05
2021-01-05€3MCelta de Vigo
2021-06-10€4.5MCelta de Vigo
2021-12-22€5M1.FSV Mainz 05
2022-06-09€5M1.FSV Mainz 05
2022-11-09€7M1.FSV Mainz 05
2023-06-22€7M1.FSV Mainz 05
2023-12-20€5MGenoa CFC
2024-06-05€5MGenoa CFC
2024-12-18€5MGenoa CFC
2025-03-25€6.5MGenoa CFC
2025-06-17€6.5MGenoa CFC
2025-12-23€7MGenoa CFC
2026-05-29€5MGenoa CFC

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
+0.289

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 →

Serie A507 players · median €5.5M

Valued above 45% of the 507 Serie A players.

€100k€750k€5M€30M€5MSee them in the Explorer →

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

Valued above 70% of the 2,065 defenders.

€20k€200k€2M€20M€5MSee them in the Explorer →

Where Martín 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).