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…

Hyun-jun

Yang

RWKorea, South · Celtic FC

№ 853110Established €7.4M −0.40

Player dossierPremiership

Hyun-junYang

RWRight WingerAttack

Club
Celtic FC
League
Premiership
Nationality
Korea, South
Age
23
Height
179 cm
Foot
Right
Valued
20 May 2026

Reading the valuation

The market values Yang at €5M. Model A, which never saw Yang during training, estimates €7.4M: the market value is 33% below that estimate.

That is a factor of ×1.49. 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 €7.1M, 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.

▼ −0.40A €7.4M▼ −0.36B €7.1M
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
67
Minutes
3,639
Goals
13
Assists
8
Started
43/67
Min / app
54
Cards
4Y 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 Yang…

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 €5M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €5MModel 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

Hyun-jun Yang's percentiles among attackers: Goals per 90 61st, Assists per 90 69th, Minutes, two years 75th, Starts 59th, Minutes, last 365 days 88th, European club minutes 83rd61stGoals69thAssists75thMinutes59thStarts88thRecent83rdEurope

Dashed ring: the attacker median (50th percentile)

Minutes, last 365 days

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

2,561 this player1,301 attacker median88th percentile

0peer deciles · median line · this player ●4,703

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
Apr 2021
Peak
€5M
May 2026
Model target
€5M
May 2026
Valuations
15
1 club change
May 2026€5MCeltic FCValuation the model is trained to reproduce

May 2026: €5M, Celtic FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2021-04-02€50kGangwon FC
2021-06-22€100kGangwon FC
2021-12-26€75kGangwon FC
2022-06-18€275kGangwon FC
2022-12-27€700kGangwon FC
2023-06-22€700kGangwon FC
2023-09-22€1.5MCeltic FC
2023-12-05€2MCeltic FC
2024-05-30€2MCeltic FC
2024-12-03€2MCeltic FC
2025-03-12€2.5MCeltic FC
2025-06-17€2.5MCeltic FC
2025-12-10€2.5MCeltic FC
2026-03-05€3MCeltic FC
2026-05-20€5MCeltic FC

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
−0.397

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 →

Premiership311 players · median €400k

Valued above 92% of the 311 Premiership players.

€20k€150k€1M€7.5M€5MSee them in the Explorer →

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

Valued above 64% of the 1,583 attackers.

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

Where Yang 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).