The recordWritten before first pitch.
Written before first pitch.
Never edited after.
Since Sep 17, 2026, every prediction is frozen at first pitch. Later builds may add the result and the closing price; none may change the prediction. What follows is graded from those frozen rows, including where the book is still ahead of us.
Every market
Model cards →| Market | Backtest skill | Live test | Vs closing price |
|---|---|---|---|
| Pitcher strikeouts | 25.8% 22.5% to 28.6% | 0 of 200 0 of 7 dates | Book ahead +0.092 (+0.060 to +0.134) |
| 1+ hit | 1.4% 0.9% to 1.8% | 0 of 200 0 of 7 dates | Book ahead +0.013 (+0.001 to +0.025) |
| 2+ total bases | 1.2% 0.9% to 1.6% | 0 of 200 0 of 7 dates | Book ahead +0.010 (+0.003 to +0.020) |
| 1+ home run | 1.5% 1.1% to 1.9% | 0 of 200 0 of 7 dates | Book ahead +0.007 (+0.001 to +0.016) |
| Game total | -0.7% -3.2% to 1.8% | 0 of 200 0 of 7 dates | not measured |
| Moneyline | 1.3% -0.4% to 2.9% | 0 of 200 0 of 7 dates | Book ahead +0.023 (+0.003 to +0.043) |
| First inning (NRFI/YRFI) | – | 0 of 200 0 of 7 dates | not measured |
Did the numbers mean what they said?
1,507 settled hitter games and 168 starts, frozen before first pitch · Sep 17, 2026 to Sep 25, 2026Brier 0.2389 vs 0.2388 for always saying the average (not better). Said 56.3% on average; happened 60.6%.
Brier 0.2246 vs 0.2262 for always saying the average (better). Said 32.6% on average; happened 34.6%.
Brier 0.0926 vs 0.0944 for always saying the average (better). Said 10.7% on average; happened 10.6%.
Correlation 0.42, RMSE 2.43 strikeouts. Projected 4.71 a start on average; he got 4.62.
Each dot is an equal-sized group of games, placed at what we said against what happened, with its 95% interval. On the dashed line is honest; dots spread along it is skill. Pooled across every engine that served these games (engine v11, engine v12, engine v13, engine v14), because that is what readers saw. The samples are small: read the intervals before the dots.
Strikeouts at the line, start by start
Latest 40 of 153 graded pre-game starts over 9 dates, every engine, updated with every buildBTB's side right85 of 15355.6%
Book's favorite right88 of 15357.5%
Overs74 of 15348.4%
Brier, all rows below.260book .241 · coin .250 · lower is better
| Date | Starter | Line | BTB over | Book over | Strikeouts | Result | BTB's side |
|---|---|---|---|---|---|---|---|
| Sep 25 | Brendan Beck NYY vs BAL | 4.5 | 8.3% | 57.2% | 8 | Over | Under · wrong |
| Sep 25 | Clay Holmes CHC vs BOS | 4.5 | 28.0% | 45.1% | 3 | Under | Under · right |
| Sep 25 | Trevor Rogers BAL vs NYY | 6.5 | 56.6% | 43.3% | 4 | Under | Over · wrong |
| Sep 24 | Andrew Painter PHI vs MIL | 4.5 | 63.8% | 58.3% | 8 | Over | Over · right |
| Sep 24 | Brady Singer CIN vs ATL | 3.5 | 66.9% | 53.3% | 1 | Under | Over · wrong |
| Sep 24 | Bryan Woo SEA vs LAA | 6.5 | 56.3% | 55.2% | 8 | Over | Over · right |
| Sep 24 | Cam Schlittler NYY vs TB | 6.5 | 41.2% | 43.0% | 5 | Under | Under · right |
| Sep 24 | David Sandlin CWS vs KC | 3.5 | 61.2% | 48.5% | 7 | Over | Over · right |
| Sep 24 | Eduardo Rodriguez ARI vs COL | 4.5 | 53.1% | 53.7% | 3 | Under | Over · wrong |
| Sep 24 | Grayson Rodriguez LAA vs SEA | 4.5 | 66.9% | 57.4% | 2 | Under | Over · wrong |
| Sep 24 | Ian Seymour TB vs NYY | 6.5 | 41.1% | 42.0% | 3 | Under | Under · right |
| Sep 24 | Kumar Rocker TEX vs NYM | 4.5 | 42.1% | 42.5% | 4 | Under | Under · right |
| Sep 24 | Kyle Leahy STL vs PIT | 3.5 | 65.2% | 44.7% | 3 | Under | Over · wrong |
| Sep 24 | Mason Barnett OAK vs HOU | 3.5 | 50.3% | 49.1% | 8 | Over | Over · right |
| Sep 24 | Matthew Boyd CHC vs MIA | 4.5 | 48.4% | 48.5% | 3 | Under | Under · right |
| Sep 24 | Nick Pivetta SD vs LAD | 4.5 | 29.9% | 50.0% | 7 | Over | Under · wrong |
| Sep 24 | Paul Skenes PIT vs STL | 5.5 | 51.1% | 56.3% | 8 | Over | Over · right |
| Sep 24 | Peter Lambert HOU vs OAK | 4.5 | 61.7% | 43.7% | 6 | Over | Over · right |
| Sep 24 | Randy Dobnak KC vs CWS | 3.5 | 62.7% | 48.6% | 1 | Under | Over · wrong |
| Sep 24 | Ranger Suarez BOS vs CLE | 4.5 | 30.3% | 44.4% | 5 | Over | Under · wrong |
| Sep 24 | Tanner Gordon COL vs ARI | 3.5 | 37.4% | 48.5% | 1 | Under | Under · right |
| Sep 24 | Tyler Glasnow LAD vs SD | 6.5 | 55.3% | 55.5% | 11 | Over | Over · right |
| Sep 24 | Tyler Mahle ATL vs CIN | 5.5 | 55.2% | 54.5% | 4 | Under | Over · wrong |
| Sep 24 | Tyler Phillips MIA vs CHC | 3.5 | 45.9% | 48.0% | 2 | Under | Under · right |
| Sep 24 | Zac Thornton NYM vs TEX | 3.5 | 67.6% | 58.2% | 4 | Over | Over · right |
| Sep 23 | Aaron Nola PHI vs MIL | 5.5 | 52.4% | 47.9% | 8 | Over | Over · right |
| Sep 23 | Andrew Abbott CIN vs ATL | 3.5 | 64.5% | 54.8% | 6 | Over | Over · right |
| Sep 23 | Cesar Perdomo SF vs MIN | 3.5 | 49.6% | 48.0% | 2 | Under | Under · right |
| Sep 23 | Chris Sale ATL vs CIN | 7.5 | 57.2% | 46.4% | 10 | Over | Over · right |
| Sep 23 | Connor Prielipp MIN vs SF | 5.5 | 63.2% | 42.2% | 3 | Under | Over · wrong |
| Sep 23 | Ethan Pecko HOU vs SEA | 3.5 | 62.6% | 58.6% | 2 | Under | Over · wrong |
| Sep 23 | Foster Griffin CLE vs BOS | 4.5 | 49.4% | 47.2% | 7 | Over | Under · wrong |
| Sep 23 | George Kirby SEA vs HOU | 4.5 | 51.9% | 54.0% | 5 | Over | Over · right |
| Sep 23 | Gerrit Cole NYY vs TB | 4.5 | 67.8% | 57.2% | 8 | Over | Over · right |
| Sep 23 | Jeffrey Springs OAK vs LAA | 4.5 | 30.8% | 51.0% | 3 | Under | Under · right |
| Sep 23 | Kevin Gausman CHC vs MIA | 5.5 | 53.1% | 55.4% | 7 | Over | Over · right |
| Sep 23 | Logan Henderson MIL vs PHI | 5.5 | 46.2% | 47.5% | 3 | Under | Under · right |
| Sep 23 | Mason Adams COL vs ARI | 3.5 | 55.8% | 44.7% | 8 | Over | Over · right |
| Sep 23 | Mason Englert TB vs NYY | 4.5 | 86.6% | 52.7% | 6 | Over | Over · right |
| Sep 23 | Matthew Liberatore STL vs PIT | 4.5 | 65.8% | 55.4% | 6 | Over | Over · right |