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…

Gustavo

Sá

AMPortugal · FC Famalicão

№ 982575Elite €9.2M +1.00

Player dossierLiga Portugal

GustavoSá

AMAttacking MidfieldMidfield

Club
FC Famalicão
League
Liga Portugal
Nationality
Portugal
Age
21
Height
189 cm
Foot
Right
Valued
28 May 2026

Reading the valuation

The market values Sá at €25M. Model A, which never saw Sá during training, estimates €9.2M: the market value is 171% above that estimate.

That is a factor of ×2.71. 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 €8.1M, 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.

▲ +1.00A €9.2M▲ +1.13B €8.1M
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
65
Minutes
5,254
Goals
8
Assists
10
Started
64/65
Min / app
81
Cards
14Y 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 Sá…

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 €25M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €25MModel A €9.2M

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 1,687 midfielders

Gustavo Sá's percentiles among midfielders: Goals per 90 68th, Assists per 90 77th, Minutes, two years 89th, Starts 98th, Minutes, last 365 days 85th, European club minutes 30th68thGoals77thAssists89thMinutes98thStarts85thRecent30thEurope

Dashed ring: the midfielder median (50th percentile)

Starts

Share of appearances started rather than entered from the bench.

98% this player69% midfielder median98th percentile

7%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
€400k
Sept 2022
Peak
€25M
May 2026
Model target
€25M
May 2026
Valuations
13
0 club changes
May 2026€25MFC FamalicãoValuation the model is trained to reproduce

May 2026: €25M, FC Famalicão. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2022-09-16€400kFC Famalicão
2022-11-01€800kFC Famalicão
2023-03-02€1MFC Famalicão
2023-06-16€1.5MFC Famalicão
2023-12-27€3MFC Famalicão
2024-03-08€6MFC Famalicão
2024-06-06€8MFC Famalicão
2024-12-19€10MFC Famalicão
2025-03-31€13MFC Famalicão
2025-05-30€16MFC Famalicão
2025-12-18€16MFC Famalicão
2026-03-19€18MFC Famalicão
2026-05-28€25MFC Famalicão

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
+0.999

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 →

Liga Portugal423 players · median €1M

Valued above 93% of the 423 Liga Portugal players.

€20k€200k€2M€20M€25MSee them in the Explorer →

Midfielders, all leagues1,687 players · median €2M

Valued above 91% of the 1,687 midfielders.

€20k€200k€2M€20M€25MSee them in the Explorer →

Where Sá 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).