The Cubs have a strong edge because their offense, lineup and platoon matchups and defense are stronger overall.
Why 70%?
6 of 15 categories could be scored from the data on file. One or both starters are unconfirmed, which lowers confidence. The 9 unscored categories are listed openly rather than guessed at, and their weight is shared across the categories that could be measured.
Offense
The away club has a strong edge in offense (113 vs 100 wRC+).
- Team wRC+ (away) 113 MLB Stats API
- Team wRC+ (home) 100 MLB Stats API
- Team OPS (away) .765 MLB Stats API
- Team OPS (home) .717 MLB Stats API
- Runs per game (away) 5.24 MLB Stats API
- Runs per game (home) 4.27 MLB Stats API
- Hard-hit % (away) Unavailable MLB Stats API
- Hard-hit % (home) Unavailable MLB Stats API
Starting Pitcher
One or both probable starters have no stat line yet.
Bullpen
Bullpen splits have not been imported for both clubs.
Lineup / Platoon
The away club has a strong edge in platoon matchups (.793 vs .733 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) .793 MLB Stats API
- OPS vs RHP (away) .756 MLB Stats API
- OPS vs LHP (home) .733 MLB Stats API
- OPS vs RHP (home) .711 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 strong edge in defense (.727 vs .708 defensive efficiency). DRS and UZR have no free public source and are left out rather than estimated.
- Defensive efficiency (away) .727 MLB Stats API
- Defensive efficiency (home) .708 MLB Stats API
- Outs Above Average (away) 71 MLB Stats API
- Outs Above Average (home) 20 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 home club has a clear edge in recent form (4-6 vs 5-5 over ten games). Ten games is a small sample, which is why this is weighted lightly.
- Last 10 (away) 4-6 MLB Stats API
- Last 10 (home) 5-5 MLB Stats API
- Last 5 run differential (away) Unavailable MLB Stats API
- Last 5 run differential (home) Unavailable MLB Stats API
- Streak (away) L2 MLB Stats API
- Streak (home) W2 MLB Stats API
Ballpark Fit
Fenway Park suppresses home runs (95 home run factor). The away club has a slight edge in how this park suits them (.180 vs .150 ISO).
- Run park factor 104 MLB park-factor baseline (multi-year estimate)
- Home run park factor 95 MLB park-factor baseline (multi-year estimate)
- Double park factor 117 MLB park-factor baseline (multi-year estimate)
- Team ISO (away) .180 MLB Stats API
- Team ISO (home) .150 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
Judged against how this season has actually gone, the rest of the model looks a little low on the home club, by about 11 points. 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 +11 pts to the Red Sox NumSOX backtest
Regression Risk
Needs ERA and FIP for both starters to compare surface results with fielding-independent ones.
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 6:00 PM.
This is a custom NumSOX estimate based on baseball statistics, not a betting line or a prediction of certainty.
- Offense (113 wRC+)
- Lineup / Platoon (.793 OPS)
- Defense (.727)
- Ballpark Fit (104 runs)
- Recent Form (4-6)
- Historical Calibration (-11 pts)
- Recent Form (5-5)
- Historical Calibration (+11 pts)
- Offense (100 wRC+)
- Lineup / Platoon (.733 OPS)
- Defense (.708)
- Ballpark Fit (95 HR)
Probable starter has not been announced and there is not enough recent rotation history to predict it responsibly.