After an overdue offensive explosion Wednesday, the Toronto Blue Jays are a game away from levelling the ALCS.
The pregame narrative: The Jays blew out the Seattle Mariners, 13-4, to set up a pivotal Game 4 matchup on Thursday night at T-Mobile Park. Luis Castillo will pitch for the home team, opposite Max Scherzer in his Toronto postseason debut.
Check out my Blue Jays vs. Mariners predictions for ALCS Game 4, featuring prop bets on Addison Barger and Anthony Santander.
Blue Jays vs. Mariners predictions
Parlay: Barger to record a hit | Santander under 0.5 hits | Over 5.5 runs (+410)
Barger to record a hit (-132): Barger broke out of a mini-slump in a major way on Wednesday night.
After an 0-for-10 start to the ALCS, Barger blasted a 414-foot home run late into Game 3. Here’s hoping he can breathe a sigh of relief and keep on slugging for the Jays.
- The left-hitting third baseman has seen the ball well from Castillo already this season, batting 3-for-5 with three doubles and a walk.
- LHBs have a .278 average and an .814 OPS off Castillo this season.
Barger often gets his money’s worth when he swings, evidenced by his 93rd-percentile bat speed and 91st-percentile hard-hit rate (per Baseball Savant).
With the platoon advantage, Barger over 1.5 bases at +190 is a pretty interesting solo play. But I’ll stick to this safer pick in a parlay format.
Barger has a .480 SLG vs. right-handed pitchers this season.
MLB SGP legs
Santander under 0.5 hits (+110): As a switch-hitter, Santander never explicitly has a platoon disadvantage. But he hasn’t set the world on fire from the left side, and his numbers against Castillo are rough.
- Santander batted .185 with a .606 OPS from the left side this year.
- Against Castillo, Santander is 1-for-9 with three strikeouts.
The first-year Blue Jay missed significant time this year due to injury, and he doesn’t seem to be 100% right in October.
He was scratched from the lineup in Game 2 with lower back tightness, and he was lifted in the fifth inning of Game 3 for a defensive replacement.
Sure, the game seemed largely out of hand at that point. But Santander’s weak fielding profile could be a factor that forces him out of any game early.
In five postseason starts, Santander is 3-for-15 (.200) and has been pulled early three times.
Toronto vs. Seattle alt total prediction
Over 5.5 runs (-315): The negative correlation with the Santander under makes this super-juiced leg a worthy SGP addition.
- This over is 7-2 in this year’s matchups between Toronto and Seattle. The average total in those games is 9.9 runs.
- Castillo has allowed eight runs on 17 hits in 10.0 innings vs. the Blue Jays this year. Both of his starts cleared this number with ease.
Castillo has been superb in recent starts, with just three runs allowed over his past 30.0 IP. But even if we see that version of him, rather than the one the Jays beat up on this year, there’s a pathway to this over.
Scherzer has allowed four or more runs in six of his past seven outings. In that span, he’s allowed 25 runs and 37 hits in 25.0 IP. Woof.
Toronto and Seattle rank No. 1 and 2, respectively, in overs rate this year (both over 55.0%), per Team Rankings.
Blue Jays vs. Mariners predictions as of 8:55 a.m. on 10/16/2025.
Jordan enjoys writing data-driven game previews and analysis articles — especially for MLB markets or NFL/NBA props. And as a proud Ohio University grad, he’ll always have a soft spot for college sports (especially if the Bobcats are involved). Previous stops include mlb.com, Sportsnet and The Athletic.