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…

Bruno Martins

Indi

CBNetherlands · Sparta Rotterdam

№ 112052Emerging €345k −0.14

Player dossierEredivisie

Bruno MartinsIndi

CBCentre-BackDefender

Club
Sparta Rotterdam
League
Eredivisie
Nationality
Netherlands
Age
34
Height
185 cm
Foot
Left
Valued
28 May 2026

Reading the valuation

The market values Indi at €300k. Model A, which never saw Indi during training, estimates €345k: the market value is 13% below that estimate.

That is a factor of ×1.15. 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 €547k, 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.

▼ −0.14A €345k▼ −0.60B €547k
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
43
Minutes
3,151
Goals
2
Assists
0
Started
36/43
Min / app
73
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 Indi…

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 €300k

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €300kModel A €345k

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

Bruno Martins Indi's percentiles among defenders: Goals per 90 69th, Assists per 90 17th, Minutes, two years 56th, Starts 53rd, Minutes, last 365 days 74th, European club minutes 64th69thGoals17thAssists56thMinutes53rdStarts74thRecent64thEurope

Dashed ring: the defender median (50th percentile)

Minutes, last 365 days

Club minutes in the final year of the window: recent involvement, or the absence of it.

2,411 this player1,687 defender median74th percentile

0peer deciles · median line · this player ●4,941

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
€150k
Aug 2010
Peak
€11.5M
Feb 2015
Model target
€300k
May 2026
Valuations
38
5 club changes
May 2026€300kSparta RotterdamValuation the model is trained to reproduce

May 2026: €300k, Sparta Rotterdam. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2010-08-04€150kFeyenoord U21
2011-01-17€250kFeyenoord U21
2011-06-22€450kFeyenoord U21
2012-01-11€600kFeyenoord Rotterdam
2012-06-30€1.3MFeyenoord Rotterdam
2012-10-09€3MFeyenoord Rotterdam
2013-01-09€4.5MFeyenoord Rotterdam
2013-05-28€5MFeyenoord Rotterdam
2014-02-11€6MFeyenoord Rotterdam
2014-08-11€8MFC Porto
2015-02-17€11.5MFC Porto
2015-07-01€11.5MFC Porto
2016-02-24€11.5MFC Porto
2016-07-29€10MFC Porto
2017-02-20€10MStoke City
2017-06-28€11MStoke City
2018-01-02€11MStoke City
2018-05-28€10MStoke City
2019-02-27€8MStoke City
2019-06-28€6.5MStoke City
2020-02-27€4.5MStoke City
2020-04-08€3.5MStoke City
2020-10-14€3.5MAZ Alkmaar
2021-03-06€3MAZ Alkmaar
2021-05-19€3MAZ Alkmaar
2021-10-04€2.5MAZ Alkmaar
2022-01-05€2.2MAZ Alkmaar
2022-06-08€2.2MAZ Alkmaar
2022-11-11€2.2MAZ Alkmaar
2023-06-23€2MAZ Alkmaar
2023-12-15€2MAZ Alkmaar
2024-03-18€1.5MAZ Alkmaar
2024-05-31€1MAZ Alkmaar
2024-12-17€800kAZ Alkmaar
2025-05-28€650kAZ Alkmaar
2025-10-02€400kSparta Rotterdam
2025-12-02€400kSparta Rotterdam
2026-05-28€300kSparta Rotterdam

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
−0.140

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 →

Eredivisie425 players · median €1M

Valued above 8% of the 425 Eredivisie players.

€75k€500k€3M€20M€300kSee them in the Explorer →

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

Valued above 9% of the 2,065 defenders.

€20k€200k€2M€20M€300kSee them in the Explorer →

Where Indi 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).