Armindo
Sieb
SSGermany · 1.FSV Mainz 05
Player dossierBundesliga
ArmindoSieb
SSSecond StrikerAttack
- Club
- 1.FSV Mainz 05
- League
- Bundesliga
- Nationality
- Germany
- Age
- 23
- Height
- 175 cm
- Foot
- Both
- Valued
- 27 May 2026
Reading the valuation
The market values Sieb at €2.5M. Model A, which never saw Sieb during training, estimates €4.8M: the market value is 48% below that estimate.
That is a factor of ×1.93. 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 €2.2M, 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
- 55
- Minutes
- 1,611
- Goals
- 4
- Assists
- 3
- Started
- 12/55
- Min / app
- 29
- 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 Sieb…
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 €2.5M
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)
European club minutes
Share of minutes played in UEFA club competitions.
3% this player0% attacker median60th 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
- €750k
- Nov 2020
- Peak
- €4M
- Jun 2024
- Model target
- €2.5M
- May 2026
- Valuations
- 15
- 3 club changes
May 2026: €2.5M, 1.FSV Mainz 05. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2020-11-11 | €750k | FC Bayern Munich U19 |
| 2021-06-14 | €1.5M | FC Bayern Munich U19 |
| 2021-12-15 | €1.5M | FC Bayern Munich II |
| 2022-06-27 | €1.5M | FC Bayern Munich II |
| 2022-11-30 | €1.5M | SpVgg Greuther Fürth |
| 2023-06-28 | €1.5M | SpVgg Greuther Fürth |
| 2023-12-15 | €2M | SpVgg Greuther Fürth |
| 2024-03-22 | €3.5M | SpVgg Greuther Fürth |
| 2024-06-06 | €4M | SpVgg Greuther Fürth |
| 2024-12-20 | €4M | 1.FSV Mainz 05 |
| 2025-06-05 | €3M | 1.FSV Mainz 05 |
| 2025-10-14 | €4M | 1.FSV Mainz 05 |
| 2025-12-19 | €3.5M | 1.FSV Mainz 05 |
| 2026-03-20 | €3M | 1.FSV Mainz 05 |
| 2026-05-27 | €2.5M | 1.FSV Mainz 05 |
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
- −0.657
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
Valued above 25% of the 451 Bundesliga players.
See them in the Explorer →Attackers, all leagues1,583 players · median €2.5M
Valued above 48% of the 1,583 attackers.
See them in the Explorer →Where Sieb appears
Watchlists and the comparison tray are kept in this browser only.
Near this valuation closest observed values: same league, then same position
- KramaricSSTSG 1899 Hoffenheim · Bundesliga€2.5M
- BaumannGKTSG 1899 Hoffenheim · Bundesliga€2.5M
- EriksenAMVfL Wolfsburg · Bundesliga€2.5M
- MainkaCB1.FC Heidenheim 1846 · Bundesliga€2.5M
- AubameyangCFOlympique Marseille · attackers€2.5M
- ZapataCFTorino FC · attackers€2.5M
- PléaCFPSV Eindhoven · attackers€2.5M
- MorenoCFVillarreal CF · attackers€2.5M
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).