Sebastian
Szymanski
AMPoland · Stade Rennais FC
Player dossierLigue 1
SebastianSzymanski
AMAttacking MidfieldMidfield
- Club
- Stade Rennais FC
- League
- Ligue 1
- Nationality
- Poland
- Age
- 27
- Height
- 174 cm
- Foot
- Left
- Valued
- 1 Jun 2026
Ligue 1Reading the valuation
The market values Szymanski at €12M. Model A, which never saw Szymanski during training, estimates €15.2M: the market value is 21% below that estimate.
That is a factor of ×1.27. 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 €20.8M, 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
- 90
- Minutes
- 5,433
- Goals
- 9
- Assists
- 14
- Started
- 61/90
- Min / app
- 60
- 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 Szymanski…
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 €12M
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 1,687 midfielders
Dashed ring: the midfielder median (50th percentile)
European club minutes
Share of minutes played in UEFA club competitions.
35% this player0% midfielder median98th 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
- €150k
- Jan 2017
- Peak
- €20M
- Dec 2023
- Model target
- €12M
- Jun 2026
- Valuations
- 27
- 5 club changes
Jun 2026: €12M, Stade Rennais FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2017-01-21 | €150k | Legia Warszawa |
| 2017-07-05 | €150k | Legia Warszawa |
| 2018-01-16 | €550k | Legia Warszawa |
| 2018-07-03 | €3M | Legia Warszawa |
| 2019-01-25 | €6M | Legia Warszawa |
| 2019-06-29 | €6M | Legia Warszawa |
| 2019-12-23 | €6M | Dinamo Moscow |
| 2020-04-08 | €5.4M | Dinamo Moscow |
| 2020-07-29 | €5.5M | Dynamo Moscow |
| 2020-10-19 | €7M | Dynamo Moscow |
| 2020-12-29 | €8M | Dynamo Moscow |
| 2021-06-02 | €8M | Dynamo Moscow |
| 2021-12-29 | €13M | Dynamo Moscow |
| 2022-06-02 | €14M | Dynamo Moscow |
| 2022-11-11 | €14M | Feyenoord Rotterdam |
| 2023-06-23 | €18M | Feyenoord Rotterdam |
| 2023-09-27 | €18M | Fenerbahce |
| 2023-12-21 | €20M | Fenerbahce |
| 2024-03-15 | €20M | Fenerbahce |
| 2024-05-31 | €19M | Fenerbahce |
| 2024-10-04 | €19M | Fenerbahce |
| 2024-12-23 | €17M | Fenerbahce |
| 2025-03-20 | €17M | Fenerbahce |
| 2025-06-18 | €15M | Fenerbahce |
| 2025-10-01 | €14M | Fenerbahce |
| 2025-12-17 | €12M | Fenerbahce |
| 2026-06-01 | €12M | Stade Rennais FC |
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
- −0.237
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 →Ligue 1423 players · median €5M
Valued above 72% of the 423 Ligue 1 players.
See them in the Explorer →Midfielders, all leagues1,687 players · median €2M
Valued above 81% of the 1,687 midfielders.
See them in the Explorer →Where Szymanski appears
- TerminalLigue 1 in the Player Explorer
- TerminalLigue 1 on the League Landscape
Watchlists and the comparison tray are kept in this browser only.
Near this valuation closest observed values: same league, then same position
- KehrerCBAS Monaco · Ligue 1€12M
- CamaraCMStade Rennais FC · Ligue 1€12M
- ÉdouardCFRC Lens · Ligue 1€12M
- PavardCBOlympique Marseille · Ligue 1€12M
- GoretzkaCMBayern Munich · midfielders€12M
- OdgaardAMBologna FC 1909 · midfielders€12M
- KoopmeinersDMAZ Alkmaar · midfielders€12M
- GruevDMLeeds United · midfielders€12M
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).