João
Mário
Player dossierSerie A
JoãoMário
RBRight-BackDefender
- Club
- Bologna FC 1909
- League
- Serie A
- Nationality
- Portugal
- Age
- 26
- Height
- 178 cm
- Foot
- Right
- Valued
- 29 May 2026
Reading the valuation
The market values Mário at €8M. Model A, which never saw Mário during training, estimates €7.9M: the market value is 2% above that estimate.
That is a factor of ×1.02. 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 €9.4M, 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
- 69
- Minutes
- 4,295
- Goals
- 2
- Assists
- 7
- Started
- 48/69
- Min / app
- 62
- 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 Mário…
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 €8M
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.
31% this player0% defender median96th 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
- €300k
- Feb 2019
- Peak
- €16M
- Mar 2023
- Model target
- €8M
- May 2026
- Valuations
- 21
- 3 club changes
May 2026: €8M, Bologna FC 1909. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2019-02-12 | €300k | FC Porto B |
| 2019-06-29 | €700k | FC Porto B |
| 2019-12-31 | €600k | FC Porto B |
| 2020-04-08 | €525k | FC Porto B |
| 2020-10-22 | €800k | FC Porto |
| 2021-01-28 | €3M | FC Porto |
| 2021-05-21 | €4M | FC Porto |
| 2021-09-21 | €7M | FC Porto |
| 2021-12-27 | €10M | FC Porto |
| 2022-03-10 | €12M | FC Porto |
| 2022-05-31 | €15M | FC Porto |
| 2022-11-01 | €12M | FC Porto |
| 2023-03-02 | €16M | FC Porto |
| 2023-06-16 | €16M | FC Porto |
| 2023-12-27 | €16M | FC Porto |
| 2024-06-06 | €15M | FC Porto |
| 2024-12-19 | €14M | FC Porto |
| 2025-03-31 | €10M | FC Porto |
| 2025-05-30 | €10M | FC Porto |
| 2025-12-23 | €8.5M | Juventus FC |
| 2026-05-29 | €8M | Bologna FC 1909 |
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
- +0.018
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 →Serie A507 players · median €5.5M
Valued above 60% of the 507 Serie A players.
See them in the Explorer →Defenders, all leagues2,065 players · median €2M
Valued above 78% of the 2,065 defenders.
See them in the Explorer →Where Mário appears
- TerminalSerie A in the Player Explorer
- TerminalSerie A 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
- BruyneAMSSC Napoli · Serie A€8M
- BogaLWJuventus FC · Serie A€8M
- MeretGKSSC Napoli · Serie A€8M
- PellegriniAMAS Roma · Serie A€8M
- LaporteCBAthletic Bilbao · defenders€8M
- MaguireCBManchester United · defenders€8M
- CanceloRBFC Barcelona · defenders€8M
- ShawLBManchester United · defenders€8M
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).





