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2026-W40 · Sep 28 – Oct 4, 2026
Weekly accuracy report
Every one of the 22 games that finished this week was re-graded, scoring the 155 probabilities that had been published against actual outcomes. Lower Brier is better; 0.25 is coin-flip level.
Brier (model)
0.2023
raw 0.2030
Calibration gain
−0.0008
lower is better
Hit rate
74.8%
base 42.6%
Calibration error
12.2%
raw 9.6%
By league
| League | Games | Scored | Brier |
|---|---|---|---|
| MLB | 1 | 90 | 0.2066/ 0.2047 |
| CS2 | 19 | 46 | 0.2278/ 0.2330 |
| MLS | 1 | 13 | 0.0767/ 0.0783 |
| WNBA | 1 | 6 | 0.2133/ 0.2185 |
What changed this week
- • Graded 151 markets from yesterday. Shipped probabilities scored Brier 0.2020 (raw 0.2011; a coin flip is 0.25).
- • Adopted a isotonic calibrator for league:mlb:batter_contact (hold-out Brier 0.2198 → 0.2027, 2946 samples).
- • Adopted a isotonic calibrator for baseball:batter_contact (hold-out Brier 0.2198 → 0.2027, 2946 samples).
- • Adopted a isotonic calibrator for *:batter_contact (hold-out Brier 0.2198 → 0.2027, 2946 samples).