Seattle Mariners vs Toronto Blue Jays Game 1 Prediction - 10/12/2025
Updated October 12, 2025
Updated October 12, 2025
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.
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.
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.
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 |
Score Projection: Seattle 3 – Toronto 5
Win Probability: Seattle 42% – Toronto 58%
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.
Jay Sanin is the GM and Head of Sports at ATS.io. He has been writing about sports gambling since 2013, handicapping tens of thousands of sporting events. He plays sides and totals aggressively across most sports and is more selective in player prop markets. He does his own modeling across most sports, and his family is jealous of how much time he spends on his precious spreadsheets.
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