Kansas City Royals vs Seattle Mariners · All-Time
39 meetings tracked · closing-line graded
RECORD
12-27
MEETINGS
39
ATS
14-12
O / U
18-8
Key Insights
- ▸Seattle Mariners lead 27-12 across 39 tracked meetings.
- ▸Games have averaged 10.4 combined points.
- ▸Kansas City Royals have been the better ATS side (14-12).
- ▸Strong Over trend: 18-8 O/U.
Year-by-Year Record
| Season | Games | Kansas City Royals | Seattle Mariners | ATS | O / U | Avg Total |
|---|---|---|---|---|---|---|
| 2025 | 7 | 3 | 4 | 4-3 | 4-3 | 8.3 |
| 2024 | 6 | 3 | 3 | 3-3 | 4-2 | 10.3 |
| 2023 | 7 | 1 | 6 | 3-4 | 6-1 | 12.3 |
| 2022 | 6 | 2 | 4 | 4-2 | 4-2 | 12.7 |
| 2019 | 7 | 2 | 5 | — | — | 11.4 |
| 2018 | 6 | 1 | 5 | — | — | 7.2 |
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Frequently Asked Questions
What is the Kansas City Royals vs Seattle Mariners record all-time?▾
Across 39 all-time meetings, the Seattle Mariners lead the series 27-12.
What is the ATS trend in Kansas City Royals vs Seattle Mariners games?▾
ATS: Kansas City Royals are 14-12 vs the spread in these matchups. Seattle Mariners are 12-14.
Do Kansas City Royals vs Seattle Mariners games go over or under?▾
Over/under: games between Kansas City Royals and Seattle Mariners have gone over 18 times and under 8 times, with an average combined score of 10.4.
When did Kansas City Royals and Seattle Mariners last play?▾
See Last Meetings section for detailed score, spread, and total data from the most recent Kansas City Royals vs Seattle Mariners games.
Where can I see the 5-year Kansas City Royals vs Seattle Mariners history?▾
A 5-year head-to-head page tracks every Kansas City Royals vs Seattle Mariners meeting from the last five full seasons. Link at the bottom of this page.
Data coverage: Trendline's head-to-head records include closing-line-graded games from 2018–2025. Older meetings aren't in this dataset yet.