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…

Marquinhos

LWBrazil · Spartak Moscow

№ 516722Established €7.4M −0.05

Player dossierPremier Liga

Marquinhos

LWLeft WingerAttack

Club
Spartak Moscow
League
Premier Liga
Nationality
Brazil
Age
26
Height
165 cm
Foot
Right
Valued
26 May 2026

Reading the valuation

The market values Marquinhos at €7M. Model A, which never saw Marquinhos during training, estimates €7.4M: the market value is 5% below that estimate.

That is a factor of ×1.05. 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 €5.7M, 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.

▼ −0.05A €7.4M▲ +0.21B €5.7M
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
69
Minutes
4,828
Goals
10
Assists
19
Started
56/69
Min / app
70
Cards
11Y 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 Marquinhos…

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 €7M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €7MModel A €7.4M

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 1,583 attackers

Marquinhos's percentiles among attackers: Goals per 90 32nd, Assists per 90 95th, Minutes, two years 90th, Starts 84th, Minutes, last 365 days 81st, European club minutes 58th32ndGoals95thAssists90thMinutes84thStarts81stRecent58thEurope

Dashed ring: the attacker median (50th percentile)

Assists per 90

Club assists per 90 minutes in the same window.

0.35 this player0.15 attacker median95th percentile

0.00peer deciles · median line · this player ●0.73

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
€7M
May 2026
Model target
€7M
May 2026
Valuations
20
3 club changes
May 2026€7MSpartak MoscowValuation the model is trained to reproduce

May 2026: €7M, Spartak Moscow. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2018-05-23€50kClube Atlético Mineiro
2019-02-18€50kClube Atlético Mineiro
2019-10-16€250kClube Atlético Mineiro
2019-11-27€900kClube Atlético Mineiro
2020-02-20€6MClube Atlético Mineiro
2020-04-08€5.4MClube Atlético Mineiro
2020-09-09€5.5MClube Atlético Mineiro
2021-02-09€4MClube Atlético Mineiro
2021-06-17€3.5MBotev Plovdiv
2021-12-08€3.8MBotev Plovdiv
2022-06-07€3MFerencvárosi TC
2022-10-11€2MFerencvárosi TC
2023-02-22€2.5MFerencvárosi TC
2023-06-07€2.5MFerencvárosi TC
2023-12-22€3MFerencvárosi TC
2024-05-23€4MFerencvárosi TC
2024-12-12€4.5MSpartak Moscow
2025-06-04€6MSpartak Moscow
2025-12-16€6MSpartak Moscow
2026-05-26€7MSpartak Moscow

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
−0.051

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 Liga412 players · median €1M

Valued above 90% of the 412 Premier Liga players.

€50k€300k€2M€15M€7MSee them in the Explorer →

Attackers, all leagues1,583 players · median €2.5M

Valued above 70% of the 1,583 attackers.

€20k€300k€5M€75M€7MSee them in the Explorer →

Where Marquinhos 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).