The Seattle Mariners will take on the Toronto Blue Jays in Game 1 of the 2025 American League Championship Series on Sunday night. The Blue Jays took out the New York Yankees in four games to get to the ALCS, while the Mariners needed a 15-inning walk-off win in Game 5 over the Detroit Tigers to move on. Here, I break down this series-opening game and bring you my Mariners vs Blue Jays Game 1 prediction.
Our Mariners vs Blue Jays Game 1 Pick
- Pick: Toronto Blue Jays -1.5
- Confidence: ★★★☆☆
Game Snapshot
- Matchup: Seattle Mariners vs Toronto Blue Jays
- Date & Time: Sunday, October 12, 2025, 8:03 p.m. ET
- Starting Pitchers: Bryce Miller (SEA) vs Kevin Gausman (TOR)
- Stadium: Rogers Centre, Toronto
- Broadcast: FOX, Sportsnet
Key Storylines
Pitching matchup
Seattle is tabbing Bryce Miller to start Game 1 after both Luis Castillo and Logan Gilbert were used in relief during the ALDS finale. Miller’s regular-season saw him go 4-6 with a 5.68 ERA in 18 starts. In his recent ALDS outing, he lasted 4.1 innings, allowing two runs on four hits with two strikeouts before being lifted. It will be interesting to see how he performs in this situation.
Kevin Gausman will take the mound for Toronto. He comes in pitching well, having delivered in Game 1 of the ALDS by allowing one run over 5.2 innings. Gausman has proven that he can be trusted in big moments and will try to do so again in this spot.
Key Players
George Springer is one to watch in the leadoff role for the Blue Jays. He has been reliable at the plate, particularly at home, and he will try to make things happen again at the top of the Toronto order. Vladimir Guerrero Jr. had a huge ALDS against the Yankees and will try to carry that into this series opener.
Cal Raleigh is the straw that stirs the drink for the Mariners’ offense. He will try to get going after having his share of struggles against the Tigers in the last round. The Mariners’ bullpen will also be under scrutiny. Any weakness there may be exposed early in the series.
Best Player Props
| Player | Prop |
|---|---|
| Cal Raleigh (SEA) | Over 1.5 Total Bases |
| George Springer (TOR) | Over 0.5 Home Runs |
| Kevin Gausman (TOR) | Over 5.5 Strikeouts |
Betting Trends & H2H
- Toronto went 4-2 against the Mariners during the regular season.
- The road team won five of the six meetings between these teams during the regular season.
- Toronto is 2-0 at home in the postseason so far.
- Seattle is 1-1 on the road during postseason play.
Mariners vs Blue Jays Game 1 Model Projection
Score Projection: Seattle 3 – Toronto 5
Win Probability: Seattle 42% – Toronto 58%
Final Thoughts
My best bet for Game 1 of the ALCS is for the Toronto Blue Jays to win and cover the runline at home. Toronto’s offense should jump on Miller early in this game, creating some separation and relieving some of the early pressure on Gausman. I’ll take the Jays to win this game by two runs or more to set the tone for the series at home.
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- Source: https://ats.io/mlb/seattle-mariners-vs-toronto-blue-jays-game-1-prediction-10-12-2025/470728/