The Toronto Blue Jays woke up at the plate and won Game 3 on Wednesday, and they’ll look to make it two in a row over the Seattle Mariners at T-Mobile Park on Thursday, October 16.
However, my top Blue Jays vs. Mariners predictions and MLB picks expect Seattle to have an edge on the mound and win Game 4 with righty Luis Castillo turning in another tidy outing.
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Blue Jays vs Mariners Game 4 predictions
Who will win Blue Jays vs Mariners Game 4
Seattle starter Luis Castillo has been money at T-Mobile Park, and Toronto veteran Max Scherzer struggled to finish up the regular season. The Mariners take a commanding 3-1 series lead tonight.
Blue Jays vs Mariners best bet
Mariners moneyline (-125)
Pitcher-friendly T-Mobile Park has been a haven for Seattle Mariners righty Luis Castillo. The 32-year-old veteran has posted a tidy 2.95 ERA, 1.02 WHIP, and 3.46 xFIP at home across 51 stats over his three full seasons with the Mariners.
Sure, Castillo doesn’t flash the same swing-and-miss stuff of his earlier years, but he’s spun six scoreless innings this postseason, and he’s well rested after pitching 1 1/3 frames in relief in Game 5 of the ALDS.
The Toronto Blue Jays will also have a rested veteran toeing the rubber in Game 4; it’s just that Max Scherzer has been idle because he pitched poorly down the stretch.
Scherzer posted a 9.00 ERA and 1.80 WHIP while allowing opposing hitters to post a .336 batting average and 47.6% hard-hit rate across his final six starts of the regular season.
Seattle finished fifth in ISO and 12th in wOBA during the regular season against right-handed pitchers, and the Mariners rank second and fourth, respectively, in the two metrics this postseason.
Even with the Toronto bats waking up in Game 3, I’m still siding with Seattle and Castillo because of his track record at T-Mobile Park.
Blue Jays vs Mariners Game 4 same-game parlay (SGP)
As discussed, Scherzer has struggled with 25 earned runs surrendered during the highlighted six-start stretch, including four or more in five of six.
Turning to Springer, he posted an elite .327 batting average against right-handed pitchers during the regular season and is a respectable 5-for-18 in his career against Castillo. Of course, the Toronto leadoff man sports a four-game hitting streak and has recorded a hit in five of seven postseason games.
Blue Jays vs Mariners SGP
- Mariners -1.5
- Max Scherzer Over 1.5 earned runs
- George Springer Over 0.5 hits
Blue Jays vs Mariners home run pick for Game 4
Eugenio Suarez (+425)
Seattle third baseman Eugenio Suarez tied his career-high mark with 49 homers this season while posting an elite .301 ISO against righties. He’s also homered twice off Scherzer during his career.
Blue Jays vs Mariners Game 4 odds
- Moneyline: Toronto +105 | Seattle -125
- Run line: Toronto +1.5 (-200) | Seattle -1.5 (+165)
- Over/Under: Over 7.5 (-102) | Under 7.5 (-118)
Blue Jays vs Mariners trend
The Seattle Mariners have won 37 of their last 52 games at home (+17.10 Units / 20% ROI). Find more MLB betting trends for Blue Jays vs. Mariners.
How to watch Blue Jays vs Mariners and Game 4 info
| Location | T-Mobile Park, Seattle, WA |
| Date | Thursday, October 16, 2025 |
| First pitch | 8:33 p.m. ET |
| TV | FS1 |
| Blue Jays starting pitcher | Max Scherzer (Regular season: 5-5, 5.19 ERA) |
| Mariners starting pitcher | Luis Castillo (1-0, 0.00 ERA) |
Blue Jays vs Mariners latest injuries
Blue Jays vs Mariners weather
Odds are correct at the time of publishing and are subject to change.
Not intended for use in MA.
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