Jack
Harrison
LWEngland · ACF Fiorentina
Image: FootyLogos
Player dossierSerie A
JackHarrison
LWLeft WingerAttack
- Club
- ACF Fiorentina
- League
- Serie A
- Nationality
- England
- Age
- 29
- Height
- 175 cm
- Foot
- Left
- Valued
- 29 May 2026
Serie AReading the valuation
The market values Harrison at €6.5M. Model A, which never saw Harrison during training, estimates €3.4M: the market value is 93% above that estimate.
That is a factor of ×1.93. 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 €2.7M, 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
- 66
- Minutes
- 3,664
- Goals
- 2
- Assists
- 4
- Started
- 38/66
- Min / app
- 56
- Cards
- 2Y 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 Harrison…
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 €6.5M
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)
Minutes, two years
Total club minutes in the two-year window: how much the player was used.
3,664 this player2,242 attacker median76th 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
- €250k
- Mar 2016
- Peak
- €28M
- Sept 2022
- Model target
- €6.5M
- May 2026
- Valuations
- 28
- 5 club changes
May 2026: €6.5M, ACF Fiorentina. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2016-03-01 | €250k | New York City FC |
| 2016-05-30 | €150k | New York City FC |
| 2016-12-15 | €600k | New York City FC |
| 2017-05-24 | €850k | New York City FC |
| 2017-12-05 | €1.8M | New York City FC |
| 2018-02-27 | €3.5M | Middlesbrough FC |
| 2018-09-24 | €3.5M | Leeds United |
| 2019-06-13 | €4M | Leeds United |
| 2020-02-27 | €6.5M | Leeds United |
| 2020-04-08 | €5.2M | Leeds United |
| 2020-10-13 | €7M | Leeds United |
| 2020-12-17 | €9M | Leeds United |
| 2021-03-18 | €15M | Leeds United |
| 2021-06-08 | €15M | Leeds United |
| 2021-12-23 | €15M | Leeds United |
| 2022-06-15 | €18M | Leeds United |
| 2022-09-15 | €28M | Leeds United |
| 2022-11-03 | €25M | Leeds United |
| 2023-03-16 | €22M | Leeds United |
| 2023-06-20 | €22M | Leeds United |
| 2023-12-19 | €22M | Everton FC |
| 2024-05-27 | €18M | Everton FC |
| 2024-12-16 | €16M | Everton FC |
| 2025-05-30 | €14M | Everton FC |
| 2025-10-17 | €12M | Leeds United |
| 2025-12-09 | €10M | Leeds United |
| 2026-03-24 | €8M | ACF Fiorentina |
| 2026-05-29 | €6.5M | ACF Fiorentina |
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
- +0.660
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 54% of the 507 Serie A players.
See them in the Explorer →Attackers, all leagues1,583 players · median €2.5M
Valued above 70% of the 1,583 attackers.
See them in the Explorer →Where Harrison 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
- PongracicCBACF Fiorentina · Serie A€6.5M
- GaetanoDMCagliari Calcio · Serie A€6.5M
- StrefezzaRWParma Calcio 1913 · Serie A€6.5M
- SørensenCMParma Calcio 1913 · Serie A€6.5M
- LewandowskiCFFC Barcelona · attackers€7M
- BerardiRWUS Sassuolo · attackers€7M
- HonoratRWBorussia Mönchengladbach · attackers€7M
- CernyRWBesiktas JK · attackers€7M
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).