Gelson
Martins
RWPortugal · Olympiacos Piraeus
Player dossierSuper League
GelsonMartins
RWRight WingerAttack
- Club
- Olympiacos Piraeus
- League
- Super League
- Nationality
- Portugal
- Age
- 31
- Height
- 173 cm
- Foot
- Right
- Valued
- 4 Jun 2026
Super LeagueReading the valuation
The market values Martins at €2.5M. Model A, which never saw Martins during training, estimates €4.9M: the market value is 49% below that estimate.
That is a factor of ×1.95. 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 €3.5M, 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
- 64
- Minutes
- 4,526
- Goals
- 11
- Assists
- 11
- Started
- 53/64
- Min / app
- 71
- 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 Martins…
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.
29% this player0% attacker median94th 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
- €800k
- Jul 2015
- Peak
- €35M
- Jun 2018
- Model target
- €2.5M
- Jun 2026
- Valuations
- 30
- 3 club changes
Jun 2026: €2.5M, Olympiacos Piraeus. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2015-07-01 | €800k | Sporting CP |
| 2015-10-07 | €2M | Sporting CP |
| 2016-02-24 | €5M | Sporting CP |
| 2016-07-29 | €6M | Sporting CP |
| 2016-10-31 | €12M | Sporting CP |
| 2017-02-22 | €15M | Sporting CP |
| 2017-06-26 | €20M | Sporting CP |
| 2018-02-07 | €30M | Sporting CP |
| 2018-06-13 | €35M | Sporting CP |
| 2018-10-31 | €30M | Atlético de Madrid |
| 2018-12-21 | €20M | Atlético de Madrid |
| 2019-03-07 | €28M | AS Monaco |
| 2019-06-03 | €28M | AS Monaco |
| 2019-12-19 | €25M | AS Monaco |
| 2020-04-08 | €20M | AS Monaco |
| 2020-10-12 | €20M | AS Monaco |
| 2021-06-04 | €18M | AS Monaco |
| 2021-12-16 | €18M | AS Monaco |
| 2022-05-30 | €15M | AS Monaco |
| 2022-09-19 | €13M | AS Monaco |
| 2022-11-02 | €10M | AS Monaco |
| 2023-03-27 | €8M | AS Monaco |
| 2023-06-27 | €5M | AS Monaco |
| 2023-10-16 | €3M | AS Monaco |
| 2023-12-18 | €2.5M | AS Monaco |
| 2024-05-30 | €2.5M | Olympiacos Piraeus |
| 2024-12-18 | €3M | Olympiacos Piraeus |
| 2025-05-23 | €3M | Olympiacos Piraeus |
| 2025-12-12 | €2.5M | Olympiacos Piraeus |
| 2026-06-04 | €2.5M | Olympiacos Piraeus |
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
- −0.667
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 →Super League356 players · median €600k
Valued above 83% of the 356 Super League 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 Martins appears
Watchlists and the comparison tray are kept in this browser only.
Near this valuation closest observed values: same league, then same position
- KennyRBPAOK Thessaloniki · Super League€2.5M
- ToubaCBPanathinaikos · Super League€2.5M
- VogliaccoCBPAOK Thessaloniki · Super League€2.5M
- PenriceLBAEK Athens · Super League€2.5M
- KramaricSSTSG 1899 Hoffenheim · attackers€2.5M
- AubameyangCFOlympique Marseille · attackers€2.5M
- ZapataCFTorino FC · attackers€2.5M
- PléaCFPSV Eindhoven · 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).