MLB matchup analysis

Giants vs Red Sox Prediction, Odds and Model Pick

Friday, August 21, 2026 at Fenway Park · 7:10 PM ET

Pass

LyDia decision: Pass on Giants vs Red Sox

Lab Rating
5.7/10
Model lean
Red Sox 57.7%
Market probability
65.3%
Model edge
-7.6%
Best moneyline
-200
Sportsbooks checked
3
LyDia model
57.7%
Market
65.3%

The case for Boston Red Sox

Bats are hot: +0.030 wOBA
Boston Red Sox is outhitting its own season form over the last 15 days. Recent form is context, not a model input, but it points the same way here.

The case for San Francisco Giants

The case is thin
The model finds little going San Francisco Giants's way — it trails on the pitching plan, bullpen, and recent form. The main path to a San Francisco Giants win is variance.

Why it is not official

Below the 61.0% official gate
Win probability is 57.7%. LyDia 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 5.7/10, under the 8.0/10 required for an official pick.
Own bullpen carries risk: 7.1/10
The Boston Red Sox bullpen comes in tired. A lead after six innings is less safe than usual.

Why the setup score is what it is

Conviction: 8.36/20
LyDia leans toward Boston Red Sox, but not strongly enough to earn full conviction credit.
Pitching plan: 0/20
No meaningful starting-pitcher edge favors Boston Red Sox in this matchup.
Bullpen: 8.56/20
Both bullpens are rated tired -- this is close to a wash, not an advantage either way.
Offense: 40/40
Boston Red Sox's recent offensive form clearly outpaces San Francisco Giants's over the tracked windows.

Why the price is what it is

Team strength: 51.6%
Before any pitcher or bullpen adjustment, LyDia's team-strength model alone makes Boston Red Sox 51.6% to win. Everything below moves the price from this starting point.
Pitcher score gap: 3 points
The pitcher-score gap favors Boston Red Sox by 3 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: -0.024
The bullpen-fatigue gap between the two pens nudges the price toward San Francisco Giants. This moves the price less than the starting pitchers do, since a starter covers more of the game than the bullpen.
Net effect: 51.6% -> 57.7%
Team strength alone had Boston Red Sox at 51.6%. After the pitcher and bullpen terms, the price is 57.7% -- the same number shown as Model Lean above.
The verdict LyDia 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.

Game information

MatchupSan Francisco Giants at Boston Red Sox
DateFriday, August 21, 2026
First pitch7:10 PM ET
VenueFenway Park
Starting pitchersLogan Webb vs Sonny Gray
WeatherGame-time forecast: 71°F, 2% precipitation chance, 5 mph wind from NE.

Starting pitcher matchup

Full Pitcher Matchup Tool →
Logan WebbGiants · RHP
vs
Sonny GrayRed Sox · RHP
MetricGiantsRed Sox
Pitching planTraditional starterTraditional starter
Expected innings6⅓5⅔
ThrowsRR
LyDia pitcher score (higher is better)7376
ERA (lower is better)3.502.65
WHIP (lower is better)1.061.15
K/9 (higher is better)7.17.9
K-BB% (higher is better)13.9%15.5%
K% (higher is better)19.6%21.8%
BB% (lower is better)5.7%6.3%
BB/9 (lower is better)2.12.3
HR/9 (lower is better)0.60.9
Ground-ball rate59.0%50.4%
Fly-ball rate41.0%49.6%

Pitcher edge: LyDia gives Sonny Gray a 3-point edge over Logan Webb, driven mainly by ERA (2.65 vs 3.50) and K/9 (7.9 vs 7.1).

How to read this: the scorecards above name the starters; every number lives in this table. Highlighted cells mark a gap big enough to matter. K% and BB% are strikeout and walk rate as a share of batters faced -- K-BB% is the two combined into one skill number. HR/9 is home runs allowed per nine innings. Ground-ball and fly-ball rate are neither good nor bad on their own: high ground-ball pitchers trade strikeouts for double plays and fewer home runs, and on this data source the two rates are complementary (they add to 100%), not independent reads.

Strikeout Projections Full strikeout projections →

Logan Webb strikeouts
4.4 LyDia projected Ks
No K play · -0.1K difference is below LyDia's 0.7K threshold
Market 4.5K · O -105 / U -108 · 6 books
Sonny Gray strikeouts
4.5 LyDia projected Ks
Official pick: UNDER 5.5K · -1.0K difference
Market 5.5K · O -104 / U -116 · 6 books

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

Giants are 3-7 in their last 10, averaging 2.8 runs per game over the last 15 days, and hitting below their season form; Red Sox are 4-6 in their last 10, averaging 5.9 runs per game over the last 15 days, and swinging above their season form. On the season Red Sox carry the better run differential per game (+0.75 against -0.60).

MetricGiantsRed Sox
Last 103-74-6
Last 10 by venue (away team on the road, home team at home)3-7 on the road7-3 at home
OPS, last 15 days0.5910.807
wOBA, last 15 days (hot/cold read)0.2650.351
Runs per game, last 15 days2.85.9
K% last 15 days (lower is better)24.8%18.8%

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 daysGiantsRed Sox
OPS0.654 (-0.055 vs szn)0.795 (+0.067 vs szn)
Runs per game3.85 (-0.193 vs szn)5.57 (+1.044 vs szn)
wOBA (model offense input)0.292 (-0.019 vs szn)0.347 (+0.026 vs szn)
K% (lower is better)21.8% (+0.6% vs szn)20.3% (-1.2% vs szn)

Over the last 30 days the Red Sox have been the better offense, 0.347 wOBA to 0.292. They are running hot against their own season line (+0.026 wOBA).

Season profile

Full Stats page →
MetricGiantsRed Sox
Record52-7568-59
Run differential / game (team quality)-0.60+0.75
Runs scored / game (offense, season)4.044.53
Runs allowed / game (defense, season, lower better)4.643.78
Season OPS0.7090.728
K% season (lower is better)21.2%21.5%
OPS vs opposing hand (season)0.7300.715

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. Giants and Red Sox are highlighted.

Giants
Combined risk
6.3 Tired
Fatigue
6.8 Tired
Efficiency
6.0 Effective
Red Sox
Combined risk
7.1 Tired
Fatigue
7.8 Tired
Efficiency
6.5 Effective

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.

MetricGiantsRed Sox
Fatigue6.8/10, Tired7.8/10, Tired
Efficiency6.0/10, Effective6.5/10, Effective
Combined risk6.3/10, Tired7.1/10, Tired
Relief innings, last 7 days26.727.7
Back-to-back arms66
7-day ERA2.702.60
7-day WHIP1.240.94

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

Run total projection

Full Totals Projections →
LyDia projection
7.3
Market total
8.5
Projected away runs
2.6
Projected home runs
4.3
Over price
-102
Under price
-113
San Francisco Giants team total
2.6 projected
Line 3.5 · O +122 / U -145
Under research lean (-0.9)
Boston Red Sox team total
4.3 projected
Line 4.5 · O +120 / U -149
No team-total lean

The model projects 1.2 runs below 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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