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…

Facundo

Medina

CBArgentina · Olympique Marseille

№ 474800Elite €9.1M +0.68

Player dossierLigue 1

FacundoMedina

CBCentre-BackDefender

Club
Olympique Marseille
League
Ligue 1
Nationality
Argentina
Age
27
Height
184 cm
Foot
Left
Valued
1 Jun 2026

Reading the valuation

The market values Medina at €18M. Model A, which never saw Medina during training, estimates €9.1M: the market value is 98% above that estimate.

That is a factor of ×1.98. 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 €5.4M, 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.

▲ +0.68A €9.1M▲ +1.21B €5.4M
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
52
Minutes
4,331
Goals
0
Assists
2
Started
51/52
Min / app
83
Cards
25Y 1R

Club matches, two years to the valuation date

The Valuation Journey

What moves Model A

Asking the prediction API to explain Model A for Medina…

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 €18M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €18MModel A €9.1M

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

Facundo Medina's percentiles among defenders: Goals per 90 18th, Assists per 90 52nd, Minutes, two years 74th, Starts 92nd, Minutes, last 365 days 53rd, European club minutes 69th18thGoals52ndAssists74thMinutes92ndStarts53rdRecent69thEurope

Dashed ring: the defender median (50th percentile)

Starts

Share of appearances started rather than entered from the bench.

98% this player83% defender median92nd 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
€50k
May 2018
Peak
€25M
Mar 2024
Model target
€18M
Jun 2026
Valuations
23
2 club changes
Jun 2026€18MOlympique MarseilleValuation the model is trained to reproduce

Jun 2026: €18M, Olympique Marseille. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2018-05-08€50kCA Talleres
2018-12-18€1.3MCA Talleres
2019-05-23€3MCA Talleres
2019-08-06€4.5MCA Talleres
2019-12-05€5MCA Talleres
2020-04-08€4.5MCA Talleres
2020-10-15€8MRC Lens
2021-04-09€10MRC Lens
2021-06-04€10MRC Lens
2021-12-16€10MRC Lens
2022-05-30€11MRC Lens
2022-09-19€13MRC Lens
2022-11-02€15MRC Lens
2023-03-27€16MRC Lens
2023-06-27€22MRC Lens
2023-12-18€22MRC Lens
2024-03-19€25MRC Lens
2024-06-03€25MRC Lens
2024-12-10€25MRC Lens
2025-06-03€25MRC Lens
2025-12-15€20MOlympique Marseille
2026-03-27€18MOlympique Marseille
2026-06-01€18MOlympique Marseille

Audit context group-level, not about this player

Audit group
non-UEFA
Population gap, Model A
+0.093 95% CI +0.063 to +0.124
This player, market vs held-out A
+0.684

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 →

Ligue 1423 players · median €5M

Valued above 82% of the 423 Ligue 1 players.

€100k€750k€5M€30M€18MSee them in the Explorer →

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

Valued above 89% of the 2,065 defenders.

€20k€200k€2M€20M€18MSee them in the Explorer →

Where Medina 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).