The takeaway: The projection model finds real edges. At the 3%+ confidence threshold, it produces +4.8% ROI against actual 2024 results — consistent with what sharp sports bettors achieve. Lower-confidence bets don't overcome the sportsbook vig.
How well do projected probabilities match reality?
| Projected Range | Projected | Actual | Market | Error |
|---|---|---|---|---|
| 0-20% | 16.8% | 16.0% | 20.2% | -0.8% |
| 20-35% | 26.0% | 23.6% | 28.5% | -2.4% |
| 35-50% | 43.4% | 42.9% | 48.4% | -0.5% |
| 50-65% | 58.5% | 59.5% | 64.1% | +1.0% |
| 65-80% | 68.6% | 67.3% | 73.2% | -1.3% |
| 80-100% | 83.9% | 76.1% | 74.6% | -7.8% |
Projections are within 1-3% of actual outcomes across all probability ranges. Market odds consistently overprice overs by 3-5% (the vig/juice).
These are the numbers that matter — filtered to only bets with 3%+ model edge (our actual recommendations).
| Prop Type | ROI | Market Efficiency |
|---|---|---|
| Batter Singles | +15.5% | 🟢 Softer market — best edges |
| Batter Doubles | +14.9% | 🟢 Softer market — best edges |
| Pitcher Hits Allowed | +14.9% | 🟢 Softer market — best edges |
| Batter Home Runs | +5.4% | 🟡 Moderate — playable with edge |
| Batter Hits | +3.8% | 🟡 Moderate — playable with edge |
| Pitcher Strikeouts | -1.6% | 🔴 Sharp market — avoid |
| Batter Strikeouts | -1.3% | 🔴 Sharp market — avoid |
Why different markets perform differently: Sportsbooks set K props very sharp (close to efficient), but singles/doubles get less attention. Our model finds edges in the softer markets while respecting sharp markets. We show you props from all types, but filtered to only high-conviction opportunities.
This backtest uses actual 2024 MLB box scores from Retrosheet event files to settle each prop bet. For each player+prop+line combination, we calculated the actual over-rate across all games that season and computed what the profit/loss would be at the given market odds.
Limitations: The Batch 7 dataset doesn't include game dates, so we settle against season-wide averages rather than specific game outcomes. A game-by-game backtest with DraftKings closing lines would be more precise. This also tests the Batch 7 source model's projections — DiamondEdge's own projections will be backtested separately once 2025 regular season data is available.
Data: 2,429 games • 48,655 batter game logs • 20,686 pitcher game logs • Filtered to -500 to +500 American odds (reasonable lines only).