Marc
Bola
LBEngland · Watford FC
Player dossierPremier League
MarcBola
LBLeft-BackDefender
- Club
- Watford FC
- League
- Premier League
- Nationality
- England
- Age
- 27
- Height
- 185 cm
- Foot
- Left
- Valued
- 3 Dec 2025
Reading the valuation
The market values Bola at €1.5M. Model A, which never saw Bola during training, estimates €1.9M: the market value is 21% below that estimate.
That is a factor of ×1.26. 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 €1.6M, 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
- 45
- Minutes
- 3,429
- Goals
- 1
- Assists
- 5
- Started
- 39/45
- Min / app
- 76
- Cards
- 5Y 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 Bola…
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 €1.5M
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 2,065 defenders
Dashed ring: the defender median (50th percentile)
Assists per 90
Club assists per 90 minutes in the same window.
0.13 this player0.04 defender median85th 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
- €100k
- Oct 2017
- Peak
- €1.8M
- Jun 2021
- Model target
- €1.5M
- Dec 2025
- Valuations
- 20
- 5 club changes
Dec 2025: €1.5M, Watford FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2017-10-24 | €100k | Bristol Rovers |
| 2019-10-17 | €500k | Middlesbrough FC |
| 2020-04-08 | €400k | Blackpool FC |
| 2020-10-15 | €400k | Middlesbrough FC |
| 2020-12-22 | €700k | Middlesbrough FC |
| 2021-03-10 | €1.2M | Middlesbrough FC |
| 2021-06-30 | €1.8M | Middlesbrough FC |
| 2021-11-24 | €1.8M | Middlesbrough FC |
| 2022-05-13 | €1.8M | Middlesbrough FC |
| 2022-10-27 | €1.8M | Middlesbrough FC |
| 2023-06-01 | €1.5M | Middlesbrough FC |
| 2023-09-27 | €1.5M | Samsunspor |
| 2023-12-21 | €1.3M | Samsunspor |
| 2024-03-15 | €1.1M | Samsunspor |
| 2024-05-31 | €1M | Samsunspor |
| 2024-10-04 | €1.2M | Samsunspor |
| 2024-12-23 | €1.2M | Samsunspor |
| 2025-03-20 | €1.5M | Samsunspor |
| 2025-06-18 | €1.5M | Samsunspor |
| 2025-12-03 | €1.5M | Watford FC |
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
- −0.232
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 →Premier League555 players · median €18M
Valued above 7% of the 555 Premier League players.
See them in the Explorer →Defenders, all leagues2,065 players · median €2M
Valued above 43% of the 2,065 defenders.
See them in the Explorer →Where Bola appears
Watchlists and the comparison tray are kept in this browser only.
Near this valuation closest observed values: same league, then same position
- WalkerRBBurnley FC · Premier League€1.5M
- TrippierRBNewcastle United · Premier League€1.5M
- VeltmanRBBrighton & Hove Albion · Premier League€1.5M
- BizotGKAston Villa · Premier League€1.5M
- TraunerCBFeyenoord Rotterdam · defenders€1.5M
- KüblerRBSC Freiburg · defenders€1.5M
- MeunierRBLOSC Lille · defenders€1.5M
- JesusCBSSC Napoli · defenders€1.5M
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).