Toronto Blue Jays vs Seattle Mariners Game 4 Prediction - 10/16/2025
Updated July 9, 2026
The Toronto Blue Jays and Seattle Mariners will face off in Game 4 of the American League Championship Series on Thursday night. The Blue Jays got a win they desperately needed on the road in Game 3 thanks to an offensive explosion against the Mariners' pitching staff. Now the Jays can even this series at two games apiece with a win here. Before first pitch from T-Mobile Park, continue reading for my Blue Jays vs Mariners Game 4 prediction.
The big story in this game is Max Scherzer taking the mound for Toronto. Scherzer hasn’t pitched yet this postseason. His regular-season results were shaky (5–5, 5.19 ERA, 1.29 WHIP), but the Jays are banking on his veteran instincts and postseason experience to help them even this series. The decision to start him in this spot is a calculated risk on Toronto's part.
Luis Castillo will get the start for Seattle. Castillo’s 2025 regular-season stats show a solid 3.54 ERA, 162 strikeouts, and a 1.18 WHIP. In the postseason, Castillo has made two appearances. He has allowed just one hit and no runs in six innings of postseason work so far. He’s shown he can perform under pressure and will look to shut Toronto's bats down in front of the home crowd.
Vladimir Guerrero Jr. remains the central figure in Toronto's lineup this postseason after a huge Game 3 for the Jays. Alejandro Kirk and Andrés Giménez have also proven they can deliver power in crucial moments. Seattle's Cal Raleigh has been a force, homering previously in the ALCS and producing consistently in October thus far. Jorge Polanco has also been clutch for the Mariners. He’s delivered go-ahead hits in multiple postseason games and will try to get a timely hit to help his team take a 3-1 lead in this series.
Player | Prop |
|---|---|
Vladimir Guerrero Jr. (TOR) | Over 0.5 Home Runs |
Jorge Polanco (SEA) | Over 1.5 Total Bases |
Max Scherzer (TOR) | Under 5.5 Strikeouts |
Luis Castillo (SEA) | Under 5.5 Strikeouts |
Score Projection: Blue Jays 5 – Mariners 6
Win Probability: Blue Jays 47%, Mariners 53%
I think that we are going to see third straight game go over the total between these teams in this series. Scherzer has to shake off some rust in his first start of this postseason and that could mean early damage from the Mariners' offense. And while Castillo is off to a strong start this postseason, the Jays' offense should do enough to help this game reach the total on Thursday night.
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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