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Early Preview Lineups: Projected Odds Posted 6 min read

Cleveland Guardians vs Boston Red Sox Preview

CLE at BOS 2026-09-23 preview: probable pitchers, projected lineups, NRFI/F5 model picks, weather, ballpark, and umpire context.

Cleveland Guardians at Boston Red Sox MLB game preview for September 23, 2026
CLE
Cleveland Guardians
Foster Griffin LHP
@
7:10 PM ET
Fenway Park
BOS
Boston Red Sox
Sonny Gray RHP
Last updated Wednesday, September 23, 2026

Key Facts

Matchup
Cleveland Guardians at Boston Red Sox
Date
Wednesday, September 23, 2026
First Pitch
7:10 PM ET
Venue
Fenway Park
Probable Starters
Foster Griffin (LHP) vs Sonny Gray (RHP)
Lineups
Projected
Odds Snapshot
Sep 23, 7:11 PM ET
Last Updated
Sep 23, 11:29 AM ET

Betting Board

Snapshot Sep 23, 7:11 PM ET
Moneyline
CLE +120
BOS -124
Total
Over 6.5 -122
Under 6.5 +100
Run Line
CLE +1.5 -220
BOS -1.5 +180

Model Angles

NRFI Model
NRFI · 60%
+5.1% edge · top pick
Projected Total
5.3
model combined runs
Park Factor
1.08
Hitter friendly · HR 1.15
First Pitch Weather
56°F
7.6 mph NE
The Cleveland Guardians visit the Boston Red Sox at 7:10 PM ET at Fenway Park. Probable starters: Foster Griffin for Cleveland Guardians opposite Sonny Gray for Boston Red Sox. Lineups are projected until first pitch. This preview is built deterministically from projected lineups, probable starters, NRFI model context, market prices, first-pitch weather, park factors, and TheCapperIO model context.
  • Starter matchup: Foster Griffin (Cleveland Guardians) vs Sonny Gray (Boston Red Sox).
  • Lineup status: projected until official release.
  • NRFI model: 60% probability, lean NRFI, +5.1% edge.

Pitching Matchup

CLE Away
Foster Griffin
LHP · 15-5 · 30 GS
ERA
3.67
WHIP
1.19
K/9
8.15
IP
166.2
Career: 3.81 ERA · 1.21 WHIP · 8.04 K/9
NRFI: 81.3%
1st Inn ERA: 3.38
BOS Home
Sonny Gray
RHP · 17-5 · 28 GS
ERA
2.82
WHIP
1.16
K/9
8.06
IP
163.0
Career: 3.52 ERA · 1.19 WHIP · 8.96 K/9
NRFI: 80.2%
1st Inn ERA: 3.69

On the season, Sonny Gray holds the ERA edge in this matchup. Foster Griffin carries a 3.67 ERA and 1.19 WHIP, while Sonny Gray sits at 2.82 ERA and 1.16 WHIP.
Strikeout rates: Foster Griffin at 8.15 K/9, Sonny Gray at 8.06 K/9.
K projections: Foster Griffin at 2.9 (line 4.5)
Sonny Gray projected at 4.0 (line 4.5).
First-inning scoring: Foster Griffin holds a 81.2% career NRFI rate, Sonny Gray at 80.2%. Combined average: 80.7%.
This is a LHP vs RHP matchup, creating potential platoon advantages in both lineups.

Strikeout Projections

Foster Griffin vs BOS
Proj: 2.9Line: 4.5
-1.6
Confidence:
Sonny Gray vs CLE
Proj: 4.0Line: 4.5
-0.5
Confidence:
View all K projections on SlateIQ

Our strikeout model weighs pitcher K rate, opponent lineup whiff tendency, park factors, and umpire zone size to project total strikeouts per starter.

Foster Griffin (Cleveland Guardians) is projected for 2.9 strikeouts against a posted line of 4.5. The projection sits 1.6 K below the line, giving the model an Under lean.
He faces a high-K lineup that strikes out at 24.1% with a 28.0% whiff rate.

Sonny Gray (Boston Red Sox) is projected for 4.0 strikeouts against a posted line of 4.5. The projection is close to the line with no actionable edge.
He faces a moderate-K lineup that strikes out at 21.7% with a 28.0% whiff rate.

The Boston Red Sox lineup is more vulnerable to strikeouts in this matchup. Boston Red Sox batters K at 24.1%, Cleveland Guardians batters at 21.7%.

NRFI & First 5 Analysis

NRFI Model
60.0%
probability of NRFI
+5.1%
market edge
Strong Signal
Market implied: 55.0%Model: 60.0%
First 5 Innings
2.9est. F5 runs
CLE
3.67 ERA
5.5 inn/start
BOS
2.82 ERA
5.8 inn/start
F5 lean: Slight BOS
CLE K Projection
Foster Griffin
2.9proj
Line: 4.5
-1.6 UNDER
Confidence
BOS K Projection
Sonny Gray
4.0proj
Line: 4.5
-0.5 NEUTRAL
Confidence
Explore all model projections

Our NRFI model analyzes both starting pitchers' first-inning profiles, the top-of-order hitters in each lineup, the umpire's historical zone, and environmental factors to produce a probability estimate. For this game, the model assigns a 60.0% probability of no runs in the first inning, compared to the market's implied probability of 54.9%.

  • That creates a moderate 5.1% edge on NRFI.
  • The best available line is NRFI -122 / YRFI +100 at FanDuel.
  • This qualifies as a top pick in our publication system.

The home plate umpire for this game has not yet been assigned. MLB typically posts assignments the morning of game day. Umpire data will be added automatically once the assignment is posted.
Our NRFI model sits at 160-154 (51.0%) on official picks this season.

Prop Edges

2 model signals detected
Foster Griffin
Strikeouts Under 4.5
Hits (1+) Strong Hit 0.5
69.9%
See all today's picks and edges

Lineup & Matchup Breakdown

Cleveland Guardians Projected
K%: 21.7
Whiff rate: 28.0%Team page
Boston Red Sox Projected
K%: 24.1
3Willson ContrerasR1B
Whiff rate: 28.0%Team page
Batter vs Pitcher matchup tool

Lineups are projected as of this writing.

Cleveland Guardians K vulnerability: 21.7% strikeout rate, 28.0% whiff rate.

Boston Red Sox K vulnerability: 24.1% strikeout rate, 28.0% whiff rate.

Ballpark, Weather & Umpire

Fenway Park
Run Factor1.08
HR Factor1.15
Full park profile
Hourly Game Forecast
56°
7 PM
8 mph
NE
56°
8 PM
8 mph
NE
56°
9 PM
8 mph
NE
56°
10 PM
8 mph
NE
  • Fenway Park carries a 1.08 run factor (hitter-friendly).
  • Home run factor: 1.15 — the park elevates HR power.
  • Park notes: Green Monster (37ft wall in left field); Pesky's Pole (302ft in right field); Triangle in center field.

First pitch forecast: 56F with 8 mph winds from the NE. Humidity: 71%.

Home plate umpire: Not yet assigned. Umpire data will be added once the assignment is posted.

Run Projections & Total

  • Our projection model puts the total at 5.3 combined runs, with Cleveland Guardians projected for 2.7 and Boston Red Sox for 2.7.
  • That's 1.2 runs below the posted total of 6.5, suggesting a lean toward the Under.
  • The run projection is essentially a coin flip between these two teams.
The Bottom Line
This is a data-first preview, not a pick. Treat the NRFI model signal as context alongside the pitching matchup. Verify current odds before placing any bet. Confirm lineups at first pitch. Bet responsibly. 1-800-GAMBLER.
This preview is generated from thecapper.io projection models and publicly available data. All projections are model estimates, not guarantees. Gamble responsibly. If you or someone you know has a gambling problem, call 1-800-GAMBLER.