The Red Sox have a strong edge because their starting pitching and recent form are stronger overall. The Astros have the advantage in how sustainable their pitching has been, which is their main counterweight.
Why 59%?
8 of 15 categories could be scored from the data on file. The 7 unscored categories are listed openly rather than guessed at, and their weight is shared across the categories that could be measured.
Offense
The home club has a slight edge in offense (100 vs 102 wRC+).
- Team wRC+ (away) 100 MLB Stats API
- Team wRC+ (home) 102 MLB Stats API
- Team OPS (away) .717 MLB Stats API
- Team OPS (home) .727 MLB Stats API
- Runs per game (away) 4.27 MLB Stats API
- Runs per game (home) 4.45 MLB Stats API
- Hard-hit % (away) Unavailable MLB Stats API
- Hard-hit % (home) Unavailable MLB Stats API
Starting Pitcher
The away club has a strong edge in starting pitching (3.15 vs 4.96 FIP).
- Starter FIP (away) 3.15 MLB Stats API
- Starter FIP (home) 4.96 MLB Stats API
- K-BB% (away) 15.4 MLB Stats API
- K-BB% (home) 10.8 MLB Stats API
- WHIP (away) 1.19 MLB Stats API
- WHIP (home) 1.55 MLB Stats API
- Opponent OPS (away) .639 MLB Stats API
- Opponent OPS (home) .817 MLB Stats API
Bullpen
Bullpen splits have not been imported for both clubs.
Lineup / Platoon
Neither club has a meaningful edge in platoon matchups (.733 vs .734 OPS in their stronger split). Starter handedness and confirmed lineups are not wired up, so this is a club-level split rather than a true lineup-versus-starter read.
- OPS vs LHP (away) .733 MLB Stats API
- OPS vs RHP (away) .711 MLB Stats API
- OPS vs LHP (home) .706 MLB Stats API
- OPS vs RHP (home) .734 MLB Stats API
- Confirmed lineup Unavailable
- Platoon advantage count Unavailable
- WAR missing from lineup Unavailable
Pitch-Type Matchup
Pitch usage and hitter results by pitch type are not in the daily snapshot yet, so this category is not scored.
Defense
The away club has a slight edge in defense (.708 vs .719 defensive efficiency). DRS and UZR have no free public source and are left out rather than estimated.
- Defensive efficiency (away) .708 MLB Stats API
- Defensive efficiency (home) .719 MLB Stats API
- Outs Above Average (away) 20 MLB Stats API
- Outs Above Average (home) -7 MLB Stats API
- Defensive Runs Saved Unavailable
- UZR Unavailable
Baserunning
Needs full player-level import for both clubs; only teams with individual hitter snapshots roll up to a team baserunning total.
Recent Form
The away club has a clear edge in recent form (5-5 vs 4-6 over ten games). Ten games is a small sample, which is why this is weighted lightly.
- Last 10 (away) 5-5 MLB Stats API
- Last 10 (home) 4-6 MLB Stats API
- Last 5 run differential (away) Unavailable MLB Stats API
- Last 5 run differential (home) Unavailable MLB Stats API
- Streak (away) W2 MLB Stats API
- Streak (home) L1 MLB Stats API
Ballpark Fit
Minute Maid Park plays big for power (105 home run factor). The home club has a slight edge in how this park suits them (.150 vs .170 ISO).
- Run park factor 101 MLB park-factor baseline (multi-year estimate)
- Home run park factor 105 MLB park-factor baseline (multi-year estimate)
- Double park factor 96 MLB park-factor baseline (multi-year estimate)
- Team ISO (away) .150 MLB Stats API
- Team ISO (home) .170 MLB Stats API
Weather
No weather feed is wired up, so temperature, wind and carry are not scored.
Rest / Fatigue
Travel, days rest and schedule density are not tracked yet.
Injuries
There is no injured-list feed, so missing WAR is not scored.
Historical Calibration
This season's results back up the rest of the model, so almost no correction is needed. That read is backtested over 52 completed games at 56% accuracy.
- Backtest sample size 52 games NumSOX backtest
- Backtest accuracy 55.8% NumSOX backtest
- Brier score 0.254 NumSOX backtest
- Calibration adjustment 0 pts to the Red Sox NumSOX backtest
Regression Risk
Neither starter's ERA is far out of line with his fielding-independent numbers.
- Starter ERA (away) 3.22 MLB Stats API
- Starter FIP (away) 3.15 MLB Stats API
- Starter ERA (home) 6.55 MLB Stats API
- Starter FIP (home) 4.96 MLB Stats API
- Team BABIP (away) Unavailable MLB Stats API
- Team BABIP (home) Unavailable MLB Stats API
Live Game State
The game has not started, so score, inning and base state carry no weight yet.
Data Sources & Freshness
Each supporting statistic above carries its source and latest available update date. Missing feeds are marked unavailable and do not receive model weight.
Estimate generated Sep 26, 2026 7:28 PM.
This is a custom NumSOX estimate based on baseball statistics, not a betting line or a prediction of certainty.
- Starting Pitcher (3.15 FIP)
- Recent Form (5-5)
- Regression Risk (+0.07 ERA-FIP)
- Regression Risk (+1.59 ERA-FIP)
- Starting Pitcher (4.96 FIP)
- Recent Form (4-6)