Seattle Mariners vs Boston Red Sox: MLB Prediction, Pick & Odds — Aug 31, 2026

SEA

64-72

PregameMon, 6:45 PM EDTMLB.TV

BOS

74-62

Verdict

Pass · no edge tonight.

The model doesn't see daylight against the posted line on this game. We don't surface negative-EV picks; check the drill-down for sub-model context.

Why this matchup

2 signals · model + market

Park factor

104 total idx

Fenway Park run environment

Park factor boosts run scoring, so contact quality matters more tonight here.

Recent form

6-4

BOS +0.3 vs SEA -2.0 margin

BOS brings the hotter last-ten margin into this matchup tonight with balance.

Fenway Park · Boston, Massachusetts

Drill down

Sub-model tables · ensemble breakdown · last meeting · book shop · player props

Pregame · scouting report

The matchup, end-to-end.

Probable starters, projected lineups, head-to-head this season, our model edge against the market — every angle on one surface.

Away starter

George Kirby

SP · #68

9-10

W-L

4.02

ERA

1.33

WHIP

126

147.2

Last 3 starts

vsPHIW(9-10)7.2 IP1 ER9 K

@MILL(8-10)3.1 IP6 ER3 K

@HOU-4.2 IP5 ER2 K

Home starter

Payton Tolle

SP · #70

8-6

W-L

3.09

ERA

1.09

WHIP

141

125.1

Last 3 starts

@MIA-5.1 IP2 ER7 K

vsARI-5.0 IP3 ER6 K

@TORW(8-6)8.0 IP0 ER4 K

Vegas line

Lines post once a sportsbook releases them.

Model edge

Win prob37% / 63%

LeanHome · 13pp

ConfidenceEdge

Head to head

SeriesBOS leads series 2-1

TypeRegular Season Series

Scouting report · pre-game

BOS vs SEA.

BOS is 6-4 recently; SEA is 5-5.

63.4%

model · BOS win prob

Recent form

BOS6–4+0.3
SEA5–5-2.0

Situational

BOS2d rest
SEA2d rest
+0.0d differential

Rest is even. BOS has 6 straight road games; SEA has 2.

Model angle

Weather and park add about 0.3 runs from the total environment.

▲Weather + park+0.3pp

Players to watch

Payton TolleBOS
6.9strikeouts · ±2.7
Payton Tolle · 6.9 K · last-10 7.2 vs season 6.4.
Logan GilbertSEA
6.2strikeouts · ±1.7
Logan Gilbert · 6.2 K · last-10 6.2 vs season 6.2.
Bryan WooSEA
5.5strikeouts · ±1.2
Bryan Woo · 5.5 K · last-10 5.4 vs season 5.7.

Aggregated from r107 anatomy · r109 CLV history · r112 calibration · r118 line moves · r124 player projections · refreshes every 5 minutes

Model ensemble · how the prediction is built

3 sub-models, blended.

Each sub-model uses a different rating substrate. Bayesian model averaging weights them by rolling Brier score so the ensemble inherits each model's strengths. Disagreement flags games where the sub-models don't see eye-to-eye — lower confidence, wider band.

63.7%

ensemble · BOS favored

Elo Static
66.4%
P(BOS win)
33%
weight
Elo Pitching
67.5%
P(BOS win)
33%
weight
Bullpen Park
67.5%
P(BOS win)
34%
weight

Disagreement

0.52 pp

weighted σ across sub-models

Confidence

97% · high

maps from disagreement

Substrate count

3 / 3 active

ones with full inputs tonight

Weights recalibrated nightly on a 90-day rolling window with strict point-in-time correctness — no model gets credit for a game it hasn't seen. Headline % is Platt-scaled per league; sub-model rows show raw BMA inputs.

Player projections

BOS vs SEA.

Per-player stat projections built from a recency-weighted blend of the last ten games, season average, and matchup context. Confidence reflects sample size and stability — the top of each list is who to watch.

128

projections · 112 high confidence

Strikeouts

Payton TolleBOS
6.9± 2.7high
Logan GilbertSEA
6.2± 1.7high
Bryan WooSEA
5.5± 1.2high

Hits

Josh NaylorSEA
1.2± 1.2high
Ceddanne RafaelaBOS
1.1± 1.0high
Nick SogardBOS
1.1± 0.9high

Total bases

Mickey GasperBOS
2.1± 2.6high
Cal RaleighSEA
2.1± 3.8high
Nick SogardBOS
2.0± 2.2high

RBIs

Mickey GasperBOS
0.8± 1.1high
Cal RaleighSEA
0.7± 1.4high
Willson ContrerasBOS
0.6± 1.0high

Earned runs

Bryce MillerSEA
3.2± 2.1medium
Bryan WooSEA
2.9± 2.2high
George KirbySEA
2.6± 2.5high

Projections recompute every 30 minutes · prop lines plug in once sportsbook ingest lands

Matchup · 2026

Team rate stats vs league

MLB Stats API

SEA

league avg

BOS

.682

OPS

.718

▶

.727

.308

OBP

.318

▶

.323

3.90

Runs / G

4.50

▶

4.47

4.13

Team ERA

4.15

▶

3.48

1.24

WHIP

1.30

▶

1.22

8.6

K / 9

8.5

8.7

The One modelEdge

Mon, Aug 31

SEA

Mariners

75-88

vs63.4%BOS

BOS★

Red Sox

84-76

SEA 36.6%win prob63.4% BOS

BOS 1568 · SEA 1473Box score→

Data via ESPN · MLB Stats API · Baseball Savant

Seattle Mariners at Boston Red Sox

The matchup, end-to-end.

BOS vs SEA.

3 sub-models, blended.

BOS vs SEA.

Team rate stats vs league