Stefan
Posch
CBAustria · 1.FSV Mainz 05
Player dossierBundesliga
StefanPosch
CBCentre-BackDefender
- Club
- 1.FSV Mainz 05
- League
- Bundesliga
- Nationality
- Austria
- Age
- 29
- Height
- 188 cm
- Foot
- Right
- Valued
- 27 May 2026
BundesligaReading the valuation
The market values Posch at €6M. Model A, which never saw Posch during training, estimates €3.5M: the market value is 74% above that estimate.
That is a factor of ×1.74. 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 €5.1M, 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
- 59
- Minutes
- 3,557
- Goals
- 1
- Assists
- 0
- Started
- 38/59
- Min / app
- 60
- Cards
- 8Y 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 Posch…
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 €6M
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)
European club minutes
Share of minutes played in UEFA club competitions.
17% this player0% 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
- €125k
- Jul 2014
- Peak
- €14M
- Dec 2019
- Model target
- €6M
- May 2026
- Valuations
- 31
- 6 club changes
May 2026: €6M, 1.FSV Mainz 05. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2014-07-03 | €125k | FC Admira Wacker Mödling |
| 2015-01-11 | €125k | FC Admira Wacker Mödling |
| 2015-06-17 | €100k | FC Admira Wacker Mödling |
| 2016-08-09 | €75k | TSG 1899 Hoffenheim II |
| 2017-02-06 | €100k | TSG 1899 Hoffenheim II |
| 2017-10-18 | €300k | TSG 1899 Hoffenheim |
| 2017-12-28 | €2.5M | TSG 1899 Hoffenheim |
| 2018-06-05 | €2.5M | TSG 1899 Hoffenheim |
| 2018-12-18 | €2.5M | TSG 1899 Hoffenheim |
| 2019-03-06 | €5.5M | TSG 1899 Hoffenheim |
| 2019-06-05 | €5.5M | TSG 1899 Hoffenheim |
| 2019-10-02 | €9M | TSG 1899 Hoffenheim |
| 2019-12-17 | €14M | TSG 1899 Hoffenheim |
| 2020-04-08 | €11M | TSG 1899 Hoffenheim |
| 2020-11-26 | €13M | TSG 1899 Hoffenheim |
| 2021-02-10 | €13M | TSG 1899 Hoffenheim |
| 2021-05-27 | €13M | TSG 1899 Hoffenheim |
| 2021-10-07 | €11M | TSG 1899 Hoffenheim |
| 2021-12-22 | €11M | TSG 1899 Hoffenheim |
| 2022-06-09 | €10M | TSG 1899 Hoffenheim |
| 2022-09-27 | €7M | Bologna FC 1909 |
| 2022-11-11 | €7M | Bologna FC 1909 |
| 2023-03-21 | €10M | Bologna FC 1909 |
| 2023-06-15 | €14M | Bologna FC 1909 |
| 2023-12-20 | €14M | Bologna FC 1909 |
| 2024-06-05 | €14M | Bologna FC 1909 |
| 2024-12-18 | €10M | Bologna FC 1909 |
| 2025-06-17 | €8M | Atalanta BC |
| 2025-10-07 | €7M | Como 1907 |
| 2025-12-23 | €5.5M | Como 1907 |
| 2026-05-27 | €6M | 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
- +0.553
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 53% of the 451 Bundesliga players.
See them in the Explorer →Defenders, all leagues2,065 players · median €2M
Valued above 73% of the 2,065 defenders.
See them in the Explorer →Where Posch appears
Watchlists and the comparison tray are kept in this browser only.
Near this valuation closest observed values: same league, then same position
- SabitzerCMBorussia Dortmund · Bundesliga€6M
- FlekkenGKBayer 04 Leverkusen · Bundesliga€6M
- AndrichDMBayer 04 Leverkusen · Bundesliga€6M
- JakicDMFC Augsburg · Bundesliga€6M
- RüdigerCBReal Madrid · defenders€6M
- DigneLBAston Villa · defenders€6M
- RomagnoliCBSS Lazio · defenders€6M
- SemedoRBFenerbahce · defenders€6M
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).