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…

Rúnar Thór

Sigurgeirsson

LBIceland · Sönderjyske Fodbold

№ 494170Emerging €613k −0.43

Player dossierSuperliga

Rúnar ThórSigurgeirsson

LBLeft-BackDefender

Club
Sönderjyske Fodbold
League
Superliga
Nationality
Iceland
Age
26
Height
186 cm
Foot
Left
Valued
25 May 2026

Reading the valuation

The market values Sigurgeirsson at €400k. Model A, which never saw Sigurgeirsson during training, estimates €613k: the market value is 35% below that estimate.

That is a factor of ×1.53. 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 €790k, 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.

▼ −0.43A €613k▼ −0.68B €790k
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
32
Minutes
2,280
Goals
1
Assists
2
Started
27/32
Min / app
71
Cards
6Y 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 Sigurgeirsson…

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 €400k

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €400kModel A €613k

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

Rúnar Thór Sigurgeirsson's percentiles among defenders: Goals per 90 56th, Assists per 90 71st, Minutes, two years 40th, Starts 54th, Minutes, last 365 days 6th, European club minutes 30th56thGoals71stAssists40thMinutes54thStarts6thRecent30thEurope

Dashed ring: the defender median (50th percentile)

Assists per 90

Club assists per 90 minutes in the same window.

0.08 this player0.04 defender median71st 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
€25k
Oct 2019
Peak
€600k
Oct 2024
Model target
€400k
May 2026
Valuations
12
3 club changes
May 2026€400kSönderjyske FodboldValuation the model is trained to reproduce

May 2026: €400k, Sönderjyske Fodbold. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2019-10-16€25kKeflavík ÍF
2020-12-01€50kKeflavík ÍF
2021-10-16€25kKeflavík ÍF
2022-12-15€75kKeflavík ÍF
2023-06-27€200kÖsters IF
2024-01-08€500kWillem II Tilburg
2024-06-10€450kWillem II Tilburg
2024-10-14€600kWillem II Tilburg
2024-12-17€600kWillem II Tilburg
2025-05-28€500kWillem II Tilburg
2025-12-15€400kSönderjyske Fodbold
2026-05-25€400kSönderjyske Fodbold

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
−0.427

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 →

Superliga256 players · median €800k

Valued above 17% of the 256 Superliga players.

€20k€150k€1M€7.5M€400kSee them in the Explorer →

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

Valued above 14% of the 2,065 defenders.

€20k€200k€2M€20M€400kSee them in the Explorer →

Where Sigurgeirsson 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).