Seattle Mariners vs Boston Red Sox — Prediction & Odds

August 31, 2026 · George Kirby vs Payton Tolle · 74°F

10.6% edge · Seattle Mariners

Seattle Mariners win

51.4%

Boston Red Sox win

48.6%

Fair line (home)

+106

Proj. total

8.32

Score distribution

How often each team scores each run total across all simulations.

Seattle Mariners (mean 4.32)Boston Red Sox (mean 4.00)

Totals

O/U line

7.5

Proj. total

8.32

Over

51.9%

Under

48.1%

Model vs. market

Side	Model	Book	Fair
Seattle Mariners	51.4%	+140	-106
Boston Red Sox	48.6%	-153	+106

Projected starters

Starter	IP	K	H	BB	R
George Kirby RHP · Seattle Mariners	5.7	5.2	6.0	1.3	2.5
Payton Tolle LHP · Boston Red Sox	5.3	5.7	4.9	1.9	2.3

Strikeout ladder

George Kirby4+ 77%6+ 42%8+ 14%

Payton Tolle4+ 83%6+ 51%8+ 20%

Per-game averages across all simulations. IP is a decimal average of outs recorded, not baseball's 5.2 notation. R is runs allowed while the starter was still in the game; the simulation models no errors, so every run is earned by construction — which is why this says R and not ER.

Seattle Mariners — projected lines

Batter	PA	1B	2B	3B	HR	BB	K	AVG	OBP	SLG	OPS
Randy Arozarena	4.8	.664	.188	.008	.159	.452	1.323	.242	.332	.403	.735
Dominic Canzone	4.7	.661	.194	.009	.196	.366	1.162	.248	.311	.435	.745
Julio Rodríguez	4.6	.733	.174	.010	.206	.333	1.083	.269	.329	.463	.792
Cal Raleigh	4.5	.458	.124	.001	.228	.463	1.412	.206	.296	.411	.707
Josh Naylor	4.3	.725	.178	.003	.151	.350	.735	.266	.331	.427	.757
Taylor Ward	4.3	.554	.146	.011	.129	.527	1.117	.228	.330	.378	.708
Cole Young	4.1	.658	.156	.028	.104	.325	.779	.251	.318	.390	.708
Weston Wilson	4.0	.474	.122	.009	.128	.358	1.307	.201	.278	.345	.623
J.P. Crawford	3.9	.559	.142	.004	.074	.487	.888	.230	.333	.340	.673

Boston Red Sox — projected lines

Batter	PA	1B	2B	3B	HR	BB	K	AVG	OBP	SLG	OPS
Roman Anthony	4.5	.717	.217	.032	.131	.446	1.143	.270	.348	.436	.784
Mickey Gasper	4.4	.729	.205	.013	.097	.323	.852	.257	.321	.386	.707
Ceddanne Rafaela	4.3	.734	.228	.028	.130	.136	.902	.270	.301	.433	.734
Wilyer Abreu	4.2	.606	.200	.020	.184	.343	.963	.262	.325	.467	.792
Nick Sogard	4.1	.686	.172	.020	.049	.336	.890	.247	.314	.343	.657
Caleb Durbin	4.0	.714	.208	.016	.100	.221	.513	.280	.336	.425	.761
Jarren Duran	3.9	.570	.184	.049	.099	.235	1.013	.248	.301	.407	.708
Trevor Story	3.8	.591	.173	.005	.110	.173	1.079	.245	.287	.389	.676
Connor Wong	3.7	.574	.177	.009	.077	.204	.925	.246	.299	.371	.670

Data notes: 20/20 lineup+starter talents from projections