Mamadou
Sarr
CBSenegal · Chelsea FC
Image: FootyLogos
Player dossierPremier League
MamadouSarr
CBCentre-BackDefender
- Club
- Chelsea FC
- League
- Premier League
- Nationality
- Senegal
- Age
- 20
- Height
- 194 cm
- Foot
- Right
- Valued
- 3 Jun 2026
Premier LeagueReading the valuation
The market values Sarr at €22M. Model A, which never saw Sarr during training, estimates €28.5M: the market value is 23% below that estimate.
That is a factor of ×1.29. 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 €12.2M, 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.
- Apps
- 51
- Minutes
- 4,155
- Goals
- 0
- Assists
- 1
- Started
- 48/51
- Min / app
- 81
- Cards
- 9Y 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 Sarr…
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 €22M
Checking APIAsking 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
Dashed ring: the defender median (50th percentile)
Starts
Share of appearances started rather than entered from the bench.
94% this player83% defender median81st percentile
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
- €1M
- Mar 2023
- Peak
- €25M
- Dec 2025
- Model target
- €22M
- Jun 2026
- Valuations
- 10
- 4 club changes
Jun 2026: €22M, Chelsea FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2023-03-27 | €1M | Olympique Lyon B |
| 2023-06-27 | €1M | Olympique Lyon B |
| 2023-12-18 | €1M | Olympique Lyon |
| 2024-06-04 | €1M | RWD Molenbeek |
| 2024-10-07 | €5M | RC Strasbourg Alsace |
| 2024-12-10 | €8M | RC Strasbourg Alsace |
| 2025-03-24 | €15M | RC Strasbourg Alsace |
| 2025-06-03 | €20M | RC Strasbourg Alsace |
| 2025-12-15 | €25M | RC Strasbourg Alsace |
| 2026-06-03 | €22M | Chelsea 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
- −0.257
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 →Premier League555 players · median €18M
Valued above 59% of the 555 Premier League players.
See them in the Explorer →Defenders, all leagues2,065 players · median €2M
Valued above 92% of the 2,065 defenders.
See them in the Explorer →Where Sarr appears
Watchlists and the comparison tray are kept in this browser only.
Near this valuation closest observed values: same league, then same position
- SalahRWLiverpool FC · Premier League€22M
- SilvaAMManchester City · Premier League€22M
- Calvert-LewinCFLeeds United · Premier League€22M
- KrejciCBWolverhampton Wanderers · Premier League€22M
- RobinsonLBFulham FC · defenders€22M
- SessegnonLBFulham FC · defenders€22M
- StruijkCBLeeds United · defenders€22M
- LucumíCBBologna FC 1909 · defenders€22M
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).