Boston Red Sox vs Seattle Mariners All-Time Record

American League
Boston Red Sox
Seattle Mariners
Red Sox lead Mariners269to199since 1977

Retrosheet history through 2025, plus 6 final games from the current feed.

2026 season series tied 3-3

By

Data updated 6 min read

At a glance

All-time since 1977 · current-feed analysis, 2002 to 2026

Boston Red Sox vs Seattle Mariners insights

Current-feed record
+19wins for Red Sox
55% Red Sox · 45% Mariners

The split has held steady across the schedule change: 13-12 since 2023.

Recent form
10-10last 20
Mariners on a 2-game streak

Mariners won 8-3 on Sep 2, 2026

Where it matters
0Postseason games

No postseason meetings since 2002.

Schedule context
  • Red Sox built the series lead before the 2023 schedule change, taking 86 of 154 decided meetings (56%).
  • Since the schedule balanced out they are 13-12, or 52% to Red Sox.

Red Sox vs Mariners complete all-time series record

Boston Red Sox and Seattle Mariners have met 468 times since 1977, never in the postseason. 289 meetings predate the current feed, which adds game-level detail from 2002.

History span
1977 to 2026
First and latest meeting
Before 2002
289
Meetings from the Retrosheet game logs
Since 2002
179
Meetings with game-level detail below
Win Percentage
99W
80W
BOS
SEA
55%45%
Boston Red SoxSeattle Mariners

Recent Games

Last 10 Games
Sep 2
BOS 3-8 SEA
SEA
Sep 1
BOS 6-9 SEA
SEA
Aug 31
BOS 9-8 SEA
BOS
Jun 21
SEA 3-1 BOS
SEA
Jun 20
SEA 1-5 BOS
BOS
Jun 19
SEA 2-6 BOS
BOS
Jun 18
SEA 1-3 BOS
BOS
Jun 17
SEA 8-0 BOS
SEA
Jun 16
SEA 0-2 BOS
BOS
Apr 24
BOS 3-4 SEA
SEA
Last Meeting
Sep 2, 2026Final
BOS
3
HOME
SEA
8
AWAY
Marinerswon by5runs
Mariners' 2nd straight in this series·Game 179 since 2002
Streaks & Momentum
Current Streak
Seattle Mariners: 2 consecutive wins
2
Avg. Margin of Victory
Games decided by 3.4 runs on average
3.4runs
Momentum (Last 10 vs Archive since 2002)
BOS-Neutral
Last 1050%
Archive since 200255.3%
SEA-Neutral
Last 1050%
Archive since 200244.7%
Last 10 Results
BOS / SEA

Record since 2002

Season Split & Biggest Wins
Regular season vs Postseason record, plus each team's largest margin of victory
Regular Season179 games
99
80
No postseason meetings appear since 2002.
Boston Red Sox Biggest Win
15–1+14 runs
Aug 14, 2015
Seattle Mariners Biggest Win
12–3+9 runs
Jun 23, 2014
Decade Breakdown
Choose a decade to scope the current-feed page
Season by Season
Season ↓BOS ↕SEA ↕Games ↕
2026336
2025336
2024437
2023336
2022617
2021437
2019437
2018437
2017336
2016437
2015437
2014156
2013617
2012549
2011549
20107310
2009246
2008639
2007459
20064610
2005336
2004549
2003527
2002459

All 24 seasons are shown in the table above.

Home / Away Split
52-26BOS HOME54-47SEA HOME
AWAY
47-54
BOS
AWAY
26-52
SEA
Retrosheet archiveComplete through 2025

Boston Red Sox vs Seattle Mariners all-time record, 1977 to 2025

Explore how this matchup changed by decade, where each lineup produced its runs, and the games that pushed the rivalry record book. This archive is a separate source window from the current-feed sections above, which start in 2002.

Games
462
Peak inning
3
Record game
32 runs
Two source windows. Current-feed sections: 179 games from 2002 to 2026. History Lab: 462 Retrosheet games from 1977 to 2025. The first refreshes with current finals; Retrosheet's published archive currently ends in 2025.

Decade balance

Select an era to inspect pace, scoring and attendance.

The information used here was obtained free of charge from and is copyrighted by Retrosheet. Interested parties may contact Retrosheet at www.retrosheet.org.

Open source archive

Betting Context

Betting context since 2002

How this pairing has settled: run margins, totals and break-even prices derived from its historical record. These are final-score frequencies, not results against a closing line. We do not hold historical sportsbook prices for these games.

One-run games
31.3%

Share of the 179 decided meetings settled by exactly one run.

Won by 2 or more
68.7%

A 2+ run margin crosses 1.5, but this is not a historical line result. Average gap: 3.4.

Average total
9.4runs

Final-score average without accounting for park, bullpen or weather.

Home side wins
59.2%

Share of decided meetings won by the listed home team.

Totals ladder

Where the combined score landed against the half-run lines a book normally posts. Half runs cannot push, so every meeting falls on one side.

LineOverUnderOver rate
7.511069
61.5%
8.5Closest to even9881
54.7%
9.577102
43%

Fair price from the base rate

The decimal price that corresponds exactly to each club's win share in this archive. It describes the record and does not estimate the next game.

Boston Red Sox
99 W · 55.3%1.81
Seattle Mariners
80 W · 44.7%2.24

A base rate is not a forecast. Starting pitchers, lineups, injuries and venue all matter more to a single game than a multi-season head-to-head record.

Last 20 meetings vs full history

One-run games
25%vs 31.3% full archive
-6.3% in the last 20
Won by 2 or more
75%vs 68.7% full archive
+6.3% in the last 20
Average total
9.1 runsvs 9.4 runs full archive
-0.3 runs in the last 20

Seasons 2023 to 2026. The comparison shows whether the last 20 final scores differ from the longer archive, without assigning a cause or predicting what comes next.

View the break-even percentages in another odds format with the odds converter, or compare current prices for Red Sox and Mariners in the oddsmatcher.

Questions about this record: Boston Red Sox vs Seattle Mariners

How do recent Boston Red Sox vs Seattle Mariners results compare with the complete record?

The latest 10 decided meetings are split 5-5. Boston Red Sox lead the decided record 269-199. The recent window is a subset of the complete series from 1977 through 2026, so the page reports the two separately.

When did the Boston Red Sox and Seattle Mariners first play each other?

The Retrosheet archive's first recorded meeting for this pairing is May 3, 1977, when Seattle Mariners won 10-8 away to Boston Red Sox. The archive covers 462 meetings from 1977 through 2025. The current feed starts in 2002 and is reported separately.

About Erik Andersson

Erik Andersson is SharkBetting's Content & Marketing Specialist. His published work focuses on betting methodology, market analysis, regulation and consumer education.

The source windows, derivations and update process for this data page are documented in the methodology above.

View full profile →

Methodology & Data Sources

Current MLB game logs come from the balldontlie API and cover the 2002 season onward. Scores and schedule anomalies are checked against the official MLB Stats API. Spring training is excluded, while results from earlier franchise identities are merged into the current club.

The all-time record and the History Lab use Retrosheet game logs through 2025, with inning lines, team totals, attendance, duration and ballpark fields when available. Final games after 2025 come from the current feed, and every section built on that feed alone is labeled as starting in 2002.

The betting context summarizes completed final scores only. It contains no sportsbook closing lines and summarizes only completed games. Report a possible error through our contact page with the matchup and game date.

Read the full H2H data methodology →

Last updated Sources: balldontlie, MLB Stats API, Retrosheet

Boston Red Sox and Seattle Mariners have met 179 times in this archive, which covers the 2002 season onward.