Stefan Bell

35 yrs · Centre-back · Germany
1.FSV Mainz 05 · Bundesliga · Foot: right · Height: 192 cm
Risk: HighConfidence: MediumSample: MediumDevelopment: LowContract: until 30 Jun 2026
Market value
€600k
Updated 6 days ago
Estimated acquisition
€161k – €808k
Estimated · 20–80% range
Model value
€522k – €2.7M
Performance-implied · estimated
Projected (24m)
€222k – €529k
Resale range · estimated
Potential value gap
-€286k – €2.5M
Model value − acquisition

Value picture

Where the market, the likely price and the model estimates sit.

Estimated acquisition€161k – €808k
Model value (performance-implied)€522k – €2.7M
Projected value (24 months)€222k – €529k
Dashed line: current market value (€600k). Bars are 20–80% model ranges; tick = median.

The model rates Stefan Bell's performance-implied value at EUR 0.5M-2.7M, above the estimated acquisition range of EUR 0.2M-0.8M. Its 24-month market value projection is EUR 0.2M-0.5M. Confidence is medium: no event-level data (xG, progressive actions) is available from the current free source, and injury history is unavailable.

Acquisition note: Contract end date unavailable: range widened by 15% each side.

Bargain Index: not assigned

What drives the score. Not a black box: each component and its level.

Age above 33 (outside validated pool)

PerformanceHigh76th pct among DEF peers (age-neutral)
AgeUnfavorable34.9 years
Acquisition costFavorableest. €425k vs market €600k
Expected appreciationNeutral-9% over ~2 years (model)
Value gapVery largeweak predictor on its own
DevelopmentLow
League translationBig-five leagueleague coefficient 0.94
Tactical fitNot evaluatedRequires event/role data not available from the current free source.
RiskHigh
Data confidenceMedium

Bargain Index = percentile (among all evaluated players) of expected 2-year value relative to estimated cost. See methodology and backtests.

Market value history

Market value ≠ transfer fee ≠ acquisition cost.

Highest recorded: €6.0M

Profile vs positional peers

Percentiles among 1268 evaluated DEF players with 900+ minutes.

Performance (last season, league)

Minutes
1041 (34% of available)
Goals + assists / 90
0.35
Context-adjusted G+A / 90
0.18
xG, xA, progression
Data unavailable
Defensive actions
Data unavailable
Performance percentile
76 (High)

Adjusted = shrunk toward positional baseline for small samples, corrected for team dominance over opponents, expressed relative to positional peers in the same league.

Context

League strength
0.94 (rank 3)
Team strength (Elo)
1485
Opponent strength
1501
Possession, role
Data unavailable

League strength 1.00 = average club of the big-five leagues. Elo includes continental matches.

Potential

Development
Low
Trajectory
improving
Breakout probability
Age > 23
Resale range (24m)
€222k – €529k

Trajectory drivers: relative output up 161% vs positional peers.

Historical comparables (8): median 2-year value change -57% (IQR -65% to -15%).

Risk profile

Overall: High

  • ▲Age 35: resale value typically declines.
  • ⚠Limited sample: 1041 league minutes last season.
  • ⚠Played under 40% of available league minutes (injury data unavailable, cause unknown).
  • ⓘContract end date unavailable (or stale in source).
  • ⓘInjury history unavailable from current data source.

League translation

What happened to players who moved from this league to the big-five leagues (observed, not a forecast).

Already playing in a big-five league.

Output is relative to positional peers in each league. Movers are a selected group (clubs buy players who fit), so treat this as context, not a guarantee.

Season-by-season (domestic league)

Context-adjusted values are model outputs.

SeasonClubLeaguePosAppsMinMin shareGAG+A/90Adj. G+A/90Opp. EloTeam EloLeague str.
2025/261.FSV Mainz 05BundesligaCB18104134%220.350.18150114850.94
2024/251.FSV Mainz 05BundesligaCB18143847%010.060.07152915150.94
2023/241.FSV Mainz 05BundesligaCB1066922%000.000.05156614891.01
2022/231.FSV Mainz 05BundesligaCB30239578%000.000.02152214961.04
2021/221.FSV Mainz 05BundesligaCB33286994%200.060.06152315071.05
2020/211.FSV Mainz 05BundesligaCB16127142%110.140.13152214811.06
2018/191.FSV Mainz 05BundesligaCB25225074%000.000.02152614881.05
2017/181.FSV Mainz 05BundesligaCB25217671%100.040.05151214441.04
2016/171.FSV Mainz 05BundesligaCB31274490%510.200.16152714501.06
2015/161.FSV Mainz 05BundesligaCB30263586%140.170.13150915081.02
2014/151.FSV Mainz 05BundesligaCB31279091%320.160.12152914811.03
2013/141.FSV Mainz 05BundesligaCB27227274%030.120.10156015091.03
2012/131.FSV Mainz 05BundesligaCB846915%000.000.05145915071.11

Cups & continental competitions

SeasonCompetitionClubAppsMinGAAvg opp. Elo
2025/26Uefa Conference League Qualifying1.FSV Mainz 052172101335
2025/26Dfb Pokal1.FSV Mainz 0514500—
2024/25Dfb Pokal1.FSV Mainz 0527900—
2023/24Dfb Pokal1.FSV Mainz 0519000—
2022/23Dfb Pokal1.FSV Mainz 0519000—
2021/22Dfb Pokal1.FSV Mainz 05327100—
2019/20Dfb Pokal1.FSV Mainz 0516700—
2018/19Dfb Pokal1.FSV Mainz 05221000—
2017/18Dfb Pokal1.FSV Mainz 05330000—
2016/17Uefa Europa League1.FSV Mainz 056540001447
2016/17Dfb Pokal1.FSV Mainz 05112000—
2015/16Dfb Pokal1.FSV Mainz 05218000—
2014/15Uefa Europa League Qualifying1.FSV Mainz 052180001370
2014/15Dfb Pokal1.FSV Mainz 05112000—
2013/14Dfb Pokal1.FSV Mainz 0519000—

Small continental samples are shown for context only and are not over-weighted.

Historical comparables

Most similar profiles 2+ years ago (same position group) and what happened next. Chosen by similarity only — failures included.

Player (then)AgeValue then~2y laterOutcome
Iván Ramis
Laliga · 2018
34€500k€650krose
Walter Samuel
Serie A · 2014
36€500k€400kfell
Alexander Madlung
Bundesliga · 2015
33€800k€250kfell
João Carlos
Premier Liga · 2015
33€1.0M€250kfell
Bernardo Espinosa
Laliga · 2023
34€1.5M€550kfell
Brede Hangeland
Premier League · 2015
34€1.0M€1.0Mflat
Marcel Ndjeng
Bundesliga · 2015
33€400k€150kfell
Mathieu Bodmer
Ligue 1 · 2016
34€1.0M€500kfell

Transfer history

Fees as reported by the source; undisclosed fees shown as unknown, never estimated.

DateFromToFeeMV at time
31 Dec 2011FrankfurtMainzFree / loan€1.3M
1 Jul 2011MainzFrankfurtFree / loan€1.5M
30 Jun 20111860 MunichMainzFree / loan€1.5M
14 Aug 2010Mainz1860 MunichFree / loan€1.0M
1 Jul 2010Mainz 05 U19MainzUnknownData unavailable
1 Jul 2008Mainz 05 U17Mainz 05 U19UnknownData unavailable
1 Jul 2007TuS Mayen U17Mainz 05 U17Free / loanData unavailable

MoneyballAI identifies statistical opportunities from available data. A player flagged as a potential bargain is not guaranteed to succeed, to transfer, to rise in value, or to generate resale profit. Market values, fees and contracts come from third-party sources; ranges are model estimates with stated confidence.