Leo
Sauer
LWSlovakia · Feyenoord Rotterdam
Image: FootyLogos
Player dossierEredivisie
LeoSauer
LWLeft WingerAttack
- Club
- Feyenoord Rotterdam
- League
- Eredivisie
- Nationality
- Slovakia
- Age
- 20
- Height
- 184 cm
- Foot
- Right
- Valued
- 28 May 2026
EredivisieReading the valuation
The market values Sauer at €7M. Model A, which never saw Sauer during training, estimates €10.8M: the market value is 35% below that estimate.
That is a factor of ×1.54. 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 €8.9M, 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.
- Apps
- 61
- Minutes
- 4,411
- Goals
- 11
- Assists
- 4
- Started
- 53/61
- Min / app
- 72
- 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 Sauer…
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 €7M
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 1,583 attackers
Dashed ring: the attacker median (50th percentile)
Starts
Share of appearances started rather than entered from the bench.
87% this player59% attacker median91st 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
- €75k
- Jun 2022
- Peak
- €7M
- Oct 2025
- Model target
- €7M
- May 2026
- Valuations
- 9
- 3 club changes
May 2026: €7M, Feyenoord Rotterdam. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2022-06-22 | €75k | MSK Zilina U19 |
| 2023-10-17 | €3M | Feyenoord Rotterdam |
| 2023-12-15 | €5M | Feyenoord Rotterdam |
| 2024-05-31 | €5M | Feyenoord Rotterdam |
| 2024-12-17 | €5M | NAC Breda |
| 2025-05-28 | €5M | NAC Breda |
| 2025-10-02 | €7M | Feyenoord Rotterdam |
| 2025-12-02 | €7M | Feyenoord Rotterdam |
| 2026-05-28 | €7M | Feyenoord Rotterdam |
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
- −0.433
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 →Eredivisie425 players · median €1M
Valued above 86% of the 425 Eredivisie players.
See them in the Explorer →Attackers, all leagues1,583 players · median €2.5M
Valued above 70% of the 1,583 attackers.
See them in the Explorer →Where Sauer appears
Watchlists and the comparison tray are kept in this browser only.
Near this valuation closest observed values: same league, then same position
- DolbergCFAjax Amsterdam · Eredivisie€7M
- HwangDMFeyenoord Rotterdam · Eredivisie€7M
- SildilliaRBPSV Eindhoven · Eredivisie€7M
- KaplanCBNEC Nijmegen · Eredivisie€7M
- LewandowskiCFFC Barcelona · attackers€7M
- BerardiRWUS Sassuolo · attackers€7M
- HonoratRWBorussia Mönchengladbach · attackers€7M
- CernyRWBesiktas JK · attackers€7M
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).