MLB Grade — 2026-09-20

How the 2026-09-20 predictions scored against actual results

Cumulative Δlog-loss vs always-pick-home: -0.0244 ± 0.0068 per game over 381 games (paired; negative = beating the baseline - currently ahead).

Yesterday	Correct	Log-loss
model	12/15	0.599
always-pick-home	8/15	0.691

Daily detail: 80% hit rate · Brier 0.204 · avg margin error 3.3 · avg total-runs error 2.7. Running: 227/381 (59.6%) · cumulative log-loss 0.667 · cumulative Brier 0.237

	Game	Pick	Predicted	Actual
✅	Yankees @ Diamondbacks	Diamondbacks (53%)	4.4–4.3	8–4 (home first)
✅	Brewers @ Orioles	Brewers (63%)	5.4–3.7	0–3 (home first)
❌	Tigers @ White Sox	Tigers (50%)	4.6–4.3	8–1 (home first)
✅	Cubs @ Reds	Cubs (57%)	5.4–4.3	1–9 (home first)
✅	Athletics @ Guardians	Guardians (66%)	5.5–3.9	1–0 (home first)
✅	Mariners @ Rockies	Mariners (54%)	5.2–4.5	1–2 (home first)
❌	Braves @ Astros	Astros (50%)	4.5–4.4	2–4 (home first)
✅	Twins @ Angels	Twins (50%)	4.5–4.1	0–8 (home first)
✅	Giants @ Dodgers	Dodgers (66%)	5.3–3.9	3–1 (home first)
✅	Phillies @ Mets	Phillies (53%)	4.8–4.1	2–7 (home first)
✅	Royals @ Pirates	Pirates (56%)	4.6–4.2	4–3 (home first)
✅	Marlins @ Padres	Padres (56%)	4.8–4.4	7–3 (home first)
✅	Nationals @ Cardinals	Cardinals (59%)	5.1–4.4	5–3 (home first)
✅	Red Sox @ Rays	Rays (54%)	4.3–4.2	5–1 (home first)
❌	Blue Jays @ Rangers	Rangers (58%)	4.7–4.1	2–7 (home first)

The headline is the paired per-game log-loss difference against a fixed always-pick-home forecast (p=0.534) on the same games, ± one standard error; daily hit rate is noisy and demoted on purpose. Reference points: 0.693 is a coin flip; the model's walk-forward backtest runs 0.680 (research/SP-BACKTEST.md).

Betting-blind Elo model (K=3, +24 home, MOV-weighted, 60% season carryover) · Can Tre Beat Vegas · whosyurgoat.app/vegas/mlb