MLB matchup analysis

Guardians vs Red Sox Prediction, Odds and Model Pick

Wednesday, September 23, 2026 at Fenway Park · 7:10 PM ET

Pass

Leo decision: Pass on Guardians vs Red Sox

Lab Rating
4.2/10
Model lean
Red Sox 60.7%
Market probability
55.9%
Model edge
+4.8%
Best moneyline
-134
Sportsbooks checked
9
Leo model
60.7%
Market
55.9%

The case for Boston Red Sox

Why Leo leans Boston Red Sox
Leo's model makes Boston Red Sox 60.7% to win. No single factor dominates — the starting pitcher matchup, the bullpen tilt the same way, enough to lean Boston Red Sox even though it does not clear the bar for a high-confidence pick.

The case for Cleveland Guardians

Their bats are hot: +0.041 wOBA
Cleveland Guardians is outhitting its own season form over the last 15 days.
Team strength favors Cleveland Guardians
Before any pitcher or bullpen adjustment, Leo's own team-strength model has Cleveland Guardians ahead (59.2% to 49.6%). The pick still comes from Boston Red Sox once the pitcher and bullpen terms are applied.

Why it is not official

Below the 61.0% official gate
Win probability is 60.7%. Leo does not make a game official below 61.0%, no matter how good the price is. This is a value spot, not a high-confidence winner.
Setup quality below the bar
Lab Rating is 4.2/10, under the 7.2/10 required for an official pick.
Opponent is swinging it
The other lineup is +0.041 wOBA above its season form over the last 15 days.

Why the setup score is what it is

Conviction: 2.84/10
Leo leans toward Boston Red Sox, but not strongly enough to earn full conviction credit.
Pitching plan: 33.33/40
Sonny Gray rates 76 on Leo's pitcher score, judged on its own merits (50-80 is the credited range). That is a strong start on its own, and it earns most or all of the available credit here.
Offense: 6.21/50
Boston Red Sox's recent form does not clearly outpace Cleveland Guardians's.

Why the price is what it is

Team strength: 49.6%
Before any pitcher or bullpen adjustment, Leo's team-strength model alone makes Boston Red Sox 49.6% to win. Everything below moves the price from this starting point.
Pitcher score gap: 6 points
The pitcher-score gap favors Boston Red Sox by 6 points. This is the biggest single mover of the price -- a large gap moves it a lot, a small gap barely moves it.
Bullpen adjustment: +0.027
The bullpen-fatigue gap between the two pens nudges the price toward Boston Red Sox. This moves the price less than the starting pitchers do, since a starter covers more of the game than the bullpen.
Net effect: 49.6% -> 60.7%
Team strength alone had Boston Red Sox at 49.6%. After the pitcher and bullpen terms, the price is 60.7% -- the same number shown as Model Lean above.
The verdict Leo passes. The combined Lab Rating did not clear the official threshold.
Read the full model output

The combined Lab Rating did not clear the official threshold.

Final result

Guardians 0, Red Sox 1

How the analysis held up

Boston Red Sox won, the side Leo's model favored.

Sonny Gray (Boston Red Sox), the starter Leo's pitcher score favored, actually outpitched Foster Griffin: 6.0 IP, 0 ER (0.00 ERA) against 6.0 IP, 1 ER (1.50 ERA). The edge held up. Both starters were sharp; the edge is a narrow one between two good outings.

The Cleveland Guardians bullpen was not flagged pregame, but it had a night worth noting: 0 earned runs allowed over 2.0 relief innings (0.00 ERA) — quietly better than the pregame read implied.

The Boston Red Sox bullpen was not flagged pregame, but it had a night worth noting: 0 earned runs allowed over 3.0 relief innings (0.00 ERA) — quietly better than the pregame read implied.

Game information

MatchupCleveland Guardians at Boston Red Sox
DateWednesday, September 23, 2026
First pitch7:10 PM ET
VenueFenway Park
Starting pitchersFoster Griffin vs Sonny Gray
WeatherGame-time forecast: 54°F, 0% precipitation chance, 5 mph wind from N.

Starting pitcher matchup

Full Pitcher Matchup Tool →
Foster GriffinGuardians · LHP
vs
Sonny GrayRed Sox · RHP
MetricGuardiansRed Sox
Pitching planTraditional starterTraditional starter
Expected innings5⅔5⅔
ThrowsLR
Leo pitcher score (higher is better)6976
ERA (lower is better)3.602.72
WHIP (lower is better)1.211.15
K/9 (higher is better)8.27.9
K-BB% (higher is better)15.6%15.1%
K% (higher is better)21.8%21.8%
BB% (lower is better)6.3%6.7%
BB/9 (lower is better)2.42.4
HR/9 (lower is better)1.20.9
Ground-ball rate52.9%49.6%
Fly-ball rate47.1%50.4%

Pitcher edge: Leo gives Sonny Gray a 7-point edge over Foster Griffin, driven mainly by ERA (2.72 vs 3.60) and HR/9 (0.85 vs 1.20).

How to read this: the scorecards above name the starters; every number lives in this table.

Strikeout Projections Full strikeout projections →

Foster Griffin strikeouts
5.1 Leo projected Ks
No K play · +0.6K difference is below Leo's 0.7K threshold
Market 4.5K · O +102 / U -123 · 6 books
Sonny Gray strikeouts
3.9 Leo projected Ks
No K play · -0.6K difference is below Leo's 0.7K threshold
Market 4.5K · O -110 / U +106 · 6 books

Same data source as the Pitcher Matchup Tool, where every starter on the slate is compared side by side.

Guardians are 8-2 in their last 10 and averaging 5.7 runs per game over the last 15 days; Red Sox are 4-6 in their last 10 and averaging 2.8 runs per game over the last 15 days. On the season Red Sox carry the better run differential per game (+0.51 against +0.01).

MetricGuardiansRed Sox
Last 108-24-6
Last 10 by venue (away team on the road, home team at home)6-4 on the road4-6 at home
OPS, last 15 days0.7950.635
wOBA, last 15 days (hot/cold read)0.3490.284
Runs per game, last 15 days5.72.8
K% last 15 days (lower is better)18.0%25.2%

Last 15 days only. Hot and cold streaks for all 30 teams live on the Stats page.

30-day offense

Full offense tool →
Last 30 daysGuardiansRed Sox
OPS0.726 (+0.035 vs szn)0.673 (-0.048 vs szn)
Runs per game4.63 (+0.503 vs szn)3.29 (-1.024 vs szn)
wOBA (model offense input)0.321 (+0.013 vs szn)0.300 (-0.019 vs szn)
K% (lower is better)18.8% (-2.2% vs szn)23.0% (+1.3% vs szn)

Over the last 30 days the Guardians have been the better offense, 0.321 wOBA to 0.300. They are running hot against their own season line (+0.013 wOBA).

Season profile

Full Stats page →
MetricGuardiansRed Sox
Record82-7584-73
Run differential / game (team quality)+0.01+0.51
Runs scored / game (offense, season)4.134.31
Runs allowed / game (defense, season, lower better)4.113.80
Season OPS0.6930.721
K% season (lower is better)21.0%21.6%
OPS vs opposing hand (season)0.7020.746

Season-long team quality, not recent form. Run differential and run environment come from the season standings; splits for all 30 teams live on the Stats page, including the run environment table.

Every team on today's slate, on any two axes you pick. Guardians and Red Sox are highlighted.

Guardians
Combined risk
5.1 Normal
Fatigue
6.1 Normal
Efficiency
7.0 Effective
Red Sox
Combined risk
4.2 Normal
Fatigue
4.3 Normal
Efficiency
5.2 Average

Risk is what the model actually uses: fatigue blended with how well the pen has pitched. High fatigue with high efficiency is a tired pen that is still getting outs.

MetricGuardiansRed Sox
Fatigue6.1/10, Normal4.3/10, Normal
Efficiency7.0/10, Effective5.2/10, Average
Combined risk5.1/10, Normal4.2/10, Normal
Relief innings, last 7 days22.314.3
Back-to-back arms53
7-day ERA1.613.14
7-day WHIP0.991.60

Fatigue measures workload. Efficiency measures recent run prevention. Combined risk is what the moneyline and totals systems use.

Run total projection

Full Totals Projections →
Leo projection
5.0
Market total
2.5
Projected away runs
3.6
Projected home runs
1.6
Over price
-162
Under price
+140
Cleveland Guardians team total
3.6 projected
Line 2.5 · O -150 / U +120
Over research lean (+1.1)
Boston Red Sox team total
1.6 projected
Line 3.5 · O +106 / U -121
Under research lean (-1.9)

The model projects 2.5 runs above the market total. A research lean still requires a setup rating of at least 7.0/10. Team totals remain research-only until their graded sample is established.

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