Nelson
Abbey
CBEngland · Rio Ave FC
Player dossierLiga Portugal
NelsonAbbey
CBCentre-BackDefender
- Club
- Rio Ave FC
- League
- Liga Portugal
- Nationality
- England
- Age
- 22
- Height
- 187 cm
- Foot
- Left
- Valued
- 28 May 2026
Liga PortugalReading the valuation
The market values Abbey at €1.5M. Model A, which never saw Abbey during training, estimates €2.1M: the market value is 29% below that estimate.
That is a factor of ×1.41. 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 €3M, 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
- 35
- Minutes
- 2,784
- Goals
- 0
- Assists
- 1
- Started
- 32/35
- Min / app
- 80
- 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 Abbey…
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)
Starts
Share of appearances started rather than entered from the bench.
91% this player83% defender median74th 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
- €150k
- Oct 2020
- Peak
- €1.5M
- May 2026
- Model target
- €1.5M
- May 2026
- Valuations
- 8
- 4 club changes
May 2026: €1.5M, Rio Ave FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2020-10-15 | €150k | FC Reading U23 |
| 2023-12-27 | €400k | Reading FC |
| 2024-05-30 | €500k | Olympiacos Piraeus |
| 2024-12-30 | €500k | Swansea City |
| 2025-03-31 | €700k | Rio Ave FC |
| 2025-05-30 | €700k | Rio Ave FC |
| 2025-12-18 | €1M | Rio Ave FC |
| 2026-05-28 | €1.5M | Rio Ave 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
- −0.345
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 →Liga Portugal423 players · median €1M
Valued above 53% of the 423 Liga Portugal 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 Abbey appears
Watchlists and the comparison tray are kept in this browser only.
Near this valuation closest observed values: same league, then same position
- JordanCFCD Tondela · Liga Portugal€1.5M
- SchettineCFMoreirense FC · Liga Portugal€1.5M
- MoreiraCMCF Estrela Amadora · Liga Portugal€1.5M
- PanzoCBRio Ave FC · Liga Portugal€1.5M
- TraunerCBFeyenoord Rotterdam · defenders€1.5M
- KüblerRBSC Freiburg · defenders€1.5M
- WalkerRBBurnley FC · defenders€1.5M
- TrippierRBNewcastle United · 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).