True Baseball Sim: GM
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The Numbers Are Measured, Not Assumed
Every rate below is counted from played games and checked against real MLB. The run that produces this table decides whether the build ships.
Independent Leagues, Not One Long Run
Leader and extreme figures take one sample per season, so the table is built from eight separate leagues: eight independent samples rather than one ageing roster measured eight times.
Ranges Wider Than The Estimate
Real seasons vary. An engine tuned to reproduce one exactly would be overfit to it, so each tail figure also prints the spread actually observed.
What Is Still Wrong
Offence drifts over a long career league: across eight simulated seasons the strikeout rate falls from about 19.9% to 15.0%. It is not aging. A fixed cohort of young pitchers improves about as much as a fixed cohort of young hitters, so it is major-league roster churn, and it is not fixed. A one-season league, which is what the table above measures, is unaffected.
Hitting
The run environment and the shape of it.
| Measure | Simulated | Real | Accepted range | Status |
|---|---|---|---|---|
| Batting Average | .248 | .243 | .235 – .262 | In range |
| On-Base Percentage | .306 | .312 | .295 – .335 | In range |
| Slugging Percentage | .385 | .399 | .370 – .440 | In range |
| BABIP | .287 | .291 | .275 – .305 | In range |
| Walk Rate | 7.9% | 8.2% | 6.8% – 9.5% | In range |
| Strikeout Rate | 19.4% | 22.6% | 18.0% – 25.0% | In range |
| Runs per Team per Game | 4.28 | 4.39 | 3.90 – 4.90 | In range |
| Home Runs per Team per Game | 1.02 | 1.12 | 0.90 – 1.35 | In range |
| Doubles per Team per Game | 1.44 | 1.60 | 1.30 – 1.90 | In range |
| Triples per Team per Game | 0.13 | 0.13 | 0.05 – 0.30 | In range |
| Stolen Bases per Team per Game | 0.81 | 0.70 | 0.45 – 1.00 | In range |
Sources: The Real Game, 2024.
Pitching
Measured from the same played games.
| Measure | Simulated | Real | Accepted range | Status |
|---|---|---|---|---|
| ERA | 4.17 | 4.08 | 3.60 – 4.60 | In range |
| Runs Allowed per 9 Above ERA | 0.12 | 0.30 | 0.00 – 0.90 | In range |
| Pitches per Plate Appearance | 3.47 | 3.90 | 3.30 – 4.30 | In range |
| Chase Rate | 30.8% | 28.5% | 22.0% – 37.0% | In range |
Sources: The Real Game, 2024; The real game: ERA runs roughly 0.3 below RA/9; Baseball Savant 2024.
Batted Ball (Statcast)
Measured off simulated contact, not sampled after the fact.
| Measure | Simulated | Real | Accepted range | Status |
|---|---|---|---|---|
| Average Exit Velocity | 91.0 | 89.0 | 86.5 – 92.0 | In range |
| Hard-Hit Rate (95+ mph) | 36.8% | 39.0% | 28.0% – 46.0% | In range |
| Barrel Rate | 7.4% | 8.0% | 5.0% – 12.0% | In range |
| Sweet-Spot Rate (8–32°) | 34.0% | 33.0% | 27.0% – 42.0% | In range |
Sources: Baseball Savant 2024.
Defence
Errors are real events with real consequences.
| Measure | Simulated | Real | Accepted range | Status |
|---|---|---|---|---|
| Errors per Game (Both Clubs) | 0.39 | 0.55 | 0.30 – 0.85 | In range |
Sources: The Real Game, 2024.
The Tails
Leaders and extremes: the median across independent leagues, with the per-season spread beside it. A league can hit every average above and still print a 1.14 ERA champion, so this is the half the audience litigates.
| Measure | Simulated (median) | Real | Accepted range | Observed | Status |
|---|---|---|---|---|---|
| Batting Champion | .332 | .332 | .310 – .365 | .321 – .347 (n=8) | In range |
| ERA Leader (Qualified) | 2.16 | 2.30 | 1.75 – 3.00 | 2.05 – 2.50 (n=8) | In range |
| Home Run Leader | 61 | 50 | 38 – 66 | 49 – 73 (n=8) | In range |
| Best offence, runs per game | 5.40 | 5.60 | 5.00 – 6.30 | 4.96 – 5.63 (n=8) | In range |
| Worst offence, runs per game | 3.26 | 3.60 | 3.10 – 4.10 | 2.83 – 3.63 (n=8) | In range |
| Most Wins | 109 | 104 | 95 – 118 | 104 – 114 (n=8) | In range |
| Fewest Wins | 53 | 55 | 40 – 66 | 43 – 59 (n=8) | In range |
Sources: Real batting titles 2015–2024: .326–.348; Real ERA titles 2015–2024: 1.66–2.86; Real home run leaders 2015–2024: 41–62; Real top team offences 2015–2024: 5.3–5.9; Real bottom team offences 2015–2024: 3.3–3.9; Real best records 2015–2024: 100–116; Real worst records 2015–2024: 41–62.
People
Ejections and injuries.
| Measure | Simulated | Real | Accepted range | Status |
|---|---|---|---|---|
| Player Ejections per Club per Season | 1.40 | 1.50 | 0.40 – 4.00 | In range |
| Share of Big-League Players Injured at Any Moment | 9.8% | 12.0% | 2.0% – 30.0% | In range |
Sources: The real game: roughly 60–80 player ejections league-wide a season; The real game: injured lists carry roughly an eighth of a roster.
Money
The shape of the pay curve, and how far apart clubs are allowed to get. A GM spends the winter here, and until 2026-08-26 none of it was measured against anything.
| Measure | Simulated | Real | Accepted range | Status |
|---|---|---|---|---|
| Average Major-League Salary | 3.9 | 4.9 | 3.0 – 7.5 | In range |
| Median Major-League Salary | 1.1 | 1.5 | 0.7 – 3.5 | In range |
| Mean to Median Salary Ratio | 3.59 | 3.20 | 1.80 – 5.50 | In range |
| Share Within 10% of the Minimum | 37.4% | 38.0% | 20.0% – 55.0% | In range |
| Median Club Payroll | 146.0 | 150.0 | 90.0 – 230.0 | In range |
| Richest to Poorest Payroll | 3.94 | 5.00 | 2.00 – 9.00 | In range |
| Clubs over the Tax Line | 2 | 9 | 2 – 16 | In range |
Sources: The Real Game, 2024: $4.9M; The Real Game, 2024: about $1.5M; The Real Game, 2024: a few paid enormously, most near the minimum; The Real Game, 2024: roughly two in five; The Real Game, 2024: about $150M; The Real Game, 2024: roughly $310M against $60M; The Real Game, 2024: nine clubs.
What is not validated yet
- Platoon splits, park factors and pitch-level sequencing are not modelled at all, so nothing about them is measured here.
- Multi-season drift. A fresh league scores about 4.1 runs a side and settles near 4.8 over eight seasons as selection reaches a steady state. That rise is bounded and decelerating —
leagueStability.test.tsfails if any season leaves the modern historical band (3.6–5.1 runs) or if the late seasons run more than 0.45 runs above the early ones — but it is a real residual, and the numbers above are measured from the first two seasons rather than from equilibrium. - Peak age. Measuring it from a snapshot of qualified hitters reads 24, below the real 26–28 — but that measurement is survivorship-biased: only the good young players reach three hundred plate appearances, while every mediocre thirty-year-old still gets them. A defensible peak-age benchmark needs the same players tracked across seasons, which needs career history (not built yet). Reporting the biased figure as if it validated anything would be worse than saying this.
- Career totals and league history are not archived, so there are no career-shape benchmarks.
- Postseason results are not separately validated against real postseason rates.
Anything in that list is a known gap, not a hidden one.
Is The Simulation Calibrated To Real Baseball?
Yes. All 36 benchmarks from 19,440 simulated games sit inside accepted MLB 2024 ranges — batting average, ERA, exit velocity, barrel rate, errors, and the payroll distribution. Known gaps are listed on the page rather than hidden.
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