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…

Arturo

Calabresi

CBItaly · Pisa Sporting Club

№ 240897Emerging €1.4M −0.54

Player dossierSerie A

ArturoCalabresi

CBCentre-BackDefender

Club
Pisa Sporting Club
League
Serie A
Nationality
Italy
Age
30
Height
186 cm
Foot
Right
Valued
29 May 2026

Reading the valuation

The market values Calabresi at €800k. Model A, which never saw Calabresi during training, estimates €1.4M: the market value is 42% below that estimate.

That is a factor of ×1.72. 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 €832k, 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.

▼ −0.54A €1.4M▼ −0.04B €832k
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
27
Minutes
1,608
Goals
0
Assists
1
Started
18/27
Min / app
60
Cards
8Y 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 Calabresi…

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 €800k

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €800kModel A €1.4M

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 2,065 defenders

Arturo Calabresi's percentiles among defenders: Goals per 90 18th, Assists per 90 61st, Minutes, two years 25th, Starts 23rd, Minutes, last 365 days 48th, European club minutes 30th18thGoals61stAssists25thMinutes23rdStarts48thRecent30thEurope

Dashed ring: the defender median (50th percentile)

Assists per 90

Club assists per 90 minutes in the same window.

0.06 this player0.04 defender median61st 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
€75k
Nov 2012
Peak
€2.8M
Dec 2019
Model target
€800k
May 2026
Valuations
29
10 club changes
May 2026€800kPisa Sporting ClubValuation the model is trained to reproduce

May 2026: €800k, Pisa Sporting Club. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2012-11-05€75kRoma U19
2013-04-27€200kRoma U19
2014-06-24€200kRoma U19
2015-06-17€300kRoma U19
2015-12-28€300kAS Livorno
2016-06-13€600kBrescia Calcio
2016-12-19€700kBrescia Calcio
2017-06-09€700kBrescia Calcio
2017-12-21€600kSpezia Calcio
2018-06-18€700kFoggia Calcio
2018-12-20€2MBologna FC 1909
2019-06-06€1.8MBologna FC 1909
2019-12-19€2.8MAmiens SC
2020-04-08€2.2MAmiens SC
2020-08-25€2.2MBologna FC 1909
2020-12-29€1.8MBologna FC 1909
2021-03-23€1.5MCagliari Calcio
2021-06-03€1.5MCagliari Calcio
2021-12-29€1.3MUS Lecce
2022-06-06€1.5MUS Lecce
2022-12-22€1.3MPisa Sporting Club
2023-06-12€1.1MPisa Sporting Club
2023-12-27€900kPisa Sporting Club
2024-06-03€900kPisa Sporting Club
2024-12-23€800kPisa Sporting Club
2025-06-02€700kPisa Sporting Club
2025-12-23€700kPisa Sporting Club
2026-03-24€800kPisa Sporting Club
2026-05-29€800kPisa Sporting Club

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
−0.543

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 4% of the 507 Serie A players.

€100k€750k€5M€30M€800kSee them in the Explorer →

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

Valued above 29% of the 2,065 defenders.

€20k€200k€2M€20M€800kSee them in the Explorer →

Where Calabresi 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).