FairValue

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  • EnvironmentOverviewWhat FairValue measures, what it found, where to go next.
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Portrait of Yan Diomande

Yan

Diomande

LWCote d'Ivoire · RB Leipzig

№ 1390649World Class €50.6M +0.58

Photo: Bryan Berlin / WikiPortraits, CC BY-SA 4.0 (background removed)

Player dossierBundesliga

YanDiomande

LWLeft WingerAttack

Club
RB Leipzig
League
Bundesliga
Nationality
Cote d'Ivoire
Age
19
Height
180 cm
Foot
Right
Valued
27 May 2026

Reading the valuation

The market values Diomande at €90M. Model A, which never saw Diomande during training, estimates €50.6M: the market value is 78% above that estimate.

That is a factor of ×1.78. 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 €17.5M, 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.

▲ +0.58A €50.6M▲ +1.64B €17.5M
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
46
Minutes
3,266
Goals
15
Assists
11
Started
37/46
Min / app
71
Cards
3Y 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 Diomande…

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 €90M

Checking API
EmergingEstablishedEliteWorld Class€2M€10M€30M€100k€1M€100MMarket €90MModel A €50.6M

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

Yan Diomande's percentiles among attackers: Goals per 90 78th, Assists per 90 90th, Minutes, two years 70th, Starts 84th, Minutes, last 365 days 91st, European club minutes 28th78thGoals90thAssists70thMinutes84thStarts91stRecent28thEurope

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.

2,724 this player1,301 attacker median91st 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
€600k
May 2025
Peak
€90M
May 2026
Model target
€90M
May 2026
Valuations
6
1 club change
May 2026€90MRB LeipzigValuation the model is trained to reproduce

May 2026: €90M, RB Leipzig. Dotted lines mark the €2M, €10M and €30M tier boundaries.

Show as a table
DateMarket valueClub
2025-05-05€600kCD Leganés
2025-06-09€1.5MCD Leganés
2025-10-14€20MRB Leipzig
2025-12-19€45MRB Leipzig
2026-03-20€75MRB Leipzig
2026-05-27€90MRB Leipzig

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
+0.576

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 →

Bundesliga451 players · median €5M

Joint 3rd highest observed value among 451 Bundesliga players.

€300k€2M€15M€100M€90MSee them in the Explorer →

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

Valued above 99% of the 1,583 attackers.

€20k€300k€5M€75M€90MSee them in the Explorer →

Where Diomande 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).