Kristoffer
Ajer
CBNorway · Brentford FC
Image: FootyLogos
Player dossierPremier League
KristofferAjer
CBCentre-BackDefender
- Club
- Brentford FC
- League
- Premier League
- Nationality
- Norway
- Age
- 28
- Height
- 198 cm
- Foot
- Right
- Valued
- 3 Jun 2026
Premier LeagueReading the valuation
The market values Ajer at €18M. Model A, which never saw Ajer during training, estimates €17.6M: 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 €2.8M, 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
- 55
- Minutes
- 3,581
- Goals
- 0
- Assists
- 2
- Started
- 41/55
- Min / app
- 65
- 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 Ajer…
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 €18M
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)
Minutes, last 365 days
Club minutes in the final year of the window: recent involvement, or the absence of it.
2,138 this player1,687 defender median66th 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
- Dec 2014
- Peak
- €18M
- Jun 2022
- Model target
- €18M
- Jun 2026
- Valuations
- 27
- 3 club changes
Jun 2026: €18M, Brentford FC. Dotted lines mark the €2M, €10M and €30M tier boundaries.
Show as a table
| Date | Market value | Club |
|---|---|---|
| 2014-12-07 | €300k | IK Start |
| 2015-08-19 | €800k | IK Start |
| 2015-12-27 | €800k | IK Start |
| 2017-02-14 | €800k | Kilmarnock FC |
| 2018-03-04 | €800k | Celtic FC |
| 2018-08-08 | €1.3M | Celtic FC |
| 2019-01-03 | €2M | Celtic FC |
| 2019-08-20 | €3M | Celtic FC |
| 2020-02-05 | €3M | Celtic FC |
| 2020-04-08 | €2.7M | Celtic FC |
| 2020-07-21 | €4M | Celtic FC |
| 2021-01-18 | €4M | Celtic FC |
| 2021-06-28 | €7M | Celtic FC |
| 2021-10-05 | €17M | Brentford FC |
| 2021-12-23 | €17M | Brentford FC |
| 2022-06-15 | €18M | Brentford FC |
| 2022-11-03 | €16M | Brentford FC |
| 2023-06-20 | €16M | Brentford FC |
| 2023-12-19 | €18M | Brentford FC |
| 2024-03-14 | €15M | Brentford FC |
| 2024-05-27 | €15M | Brentford FC |
| 2024-12-16 | €18M | Brentford FC |
| 2025-05-30 | €18M | Brentford FC |
| 2025-10-17 | €16M | Brentford FC |
| 2025-12-09 | €16M | Brentford FC |
| 2026-03-09 | €18M | Brentford FC |
| 2026-06-03 | €18M | Brentford 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
- +0.022
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 50% of the 555 Premier League players.
See them in the Explorer →Defenders, all leagues2,065 players · median €2M
Valued above 89% of the 2,065 defenders.
See them in the Explorer →Where Ajer appears
Watchlists and the comparison tray are kept in this browser only.
Near this valuation closest observed values: same league, then same position
- TrossardLWArsenal FC · Premier League€18M
- AinaRBNottingham Forest · Premier League€18M
- VicarioGKTottenham Hotspur · Premier League€18M
- RodonCBLeeds United · Premier League€18M
- AntonCBBorussia Dortmund · defenders€18M
- HernándezLBParis Saint-Germain · defenders€18M
- MittelstädtLBVfB Stuttgart · defenders€18M
- Mauro Jr.LBPSV Eindhoven · defenders€18M
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).