MLB betting preview (Oct. 17): Blue Jays vs. Mariners Game 5 ALCS predictions

Photo credit: Kevin Ng-Imagn Images
Oct 17, 2025, 13:00 EDTUpdated: Oct 17, 2025, 10:31 EDT
With a convincing 8-2 win in Game 4 of the ALCS to the tie the series at two games apiece, the Blue Jays have, at worst, come to Seattle and forced a Game 6 back in Toronto on Sunday night.
The betting underdog has won each of the first four games of this series, which has also been the road team in each matchup.
Game 5 is the most closely priced game of the season by oddsmakers, as we are likely to see a rematch of Game 1 with Kevin Gausman taking on Bryce Miller.
Let’s dive into the game odds for Friday’s matchup between the Blue Jays and Mariners, courtesy of bet365.
Blue Jays vs. Mariners Game 5 ALCS odds
Blue Jays moneyline odds | -115 |
Mariners moneyline odds | -105 |
Runline odds | Blue Jays -1.5 (+155), Mariners +1.5 (-185) |
Game total | Over 7 runs (-115), Under 7 (-105) |
Date/time | Oct. 17, 6:08 p.m. ET |
Betting Toronto Blue Jays
Max Scherzer turned back the clock with an excellent performance in Game 4, handling 5 2/3 innings innings effectively and allowing the Blue Jays bullpen to remain fairly well-rested. Though they were working with a significant lead, it was also a strong performance from the Blue Jays bullpen, which allowed zero earned runs for just the second time this postseason.
Having what were two more difficult matchups on paper, the Blue Jays will look to avoid another letdown in a rematch of Game 1, a game in which the Blue Jays closed as -165 betting favorites, which is by a wide margin the largest they have been favoured in any matchup this postseason.
Gausman shouldered the weight of the loss in his post-game presser, which was certainly not necessary given that the offence produced only one run. Gausman pitched 5 2/3 innings, allowing just three hits and two earned runs.
Through 11 1/3 innings of work this postseason, Gausman holds an ERA of 2.38 and a FIP of 3.66.
Gausman entered the playoffs in excellent form, as he pitched to an ERA of 2.80 and an xFIP of 3.25 in his final 10 appearances of the season. He struck out 24.5% of batters in that span, and held a Pitching+ rating of 102.
Based on Game 1, it wouldn’t be overly surprising if the Blue Jays were more successful in this matchup as they get a second look at Miller. As we talked about prior to Game 3, the Blue Jays had poor luck on well-hit balls in Games 1 and 2 and appeared likely for positive regression, and that statement was especially true based on the at-bats that involved Miller.
The Blue Jays held an xBA of .287 versus Miller, striking out just three times in 23 plate appearances and working three walks.
As outlined before Game 1, Miller remains a strong matchup for the Blue Jays offensively. He’s in the second percentile in terms of hard contact allowed this season and doesn’t generate a ton of swing-and-miss, and the Blue Jays have been the second-best team in the league versus right-handed pitching following the trade deadline.
Due to Anthony Santander’s injury, Isiah Kiner-Falefa made Thursday’s starting lineup and the veteran made the most of his opportunity, going 2-for-3 at the plate and laying down a successful sacrifice bunt which immediately led to two runs.
You’re obviously not going to want to count on IKF for production, but his Game 4 performance epitomized what has made this Blue Jays team so special, in that every member of the roster has had their own moments of importance this season.
Betting Seattle Mariners
Oddsmakers aren’t counting on an overly lengthy outing from Miller, as he holds a betting total of just 11.5 outs. Miller recorded 18 outs in a critical Game 1 performance, in which the Mariners pitching staff was exhausted following their 15-inning marathon win over the Detroit Tigers to get into the series.
Mariners manager Dan Wilson could be planning to use Bryan Woo following Miller in this matchup to handle a good chunk of innings. Woo has not yet pitched this postseason due to a pectoral strain, but is reportedly ready to work.
Woo held a 2.94 ERA in 30 starts this season and featured a strong underlying profile, including a 3.10 xERA and 3.33 xFIP.
The Mariners’ high-powered offence has been fairly underwhelming this postseason, but has done well to come through with runs in the timely moments of many matchups. Seattle has hit to a wRC+ of 95 this postseason, struck out 28.1% of the time, and holds the second highest soft contact rate of any playoff team.
Seattle does rank eighth in wRC+ versus righties since the trade deadline, following its acquisitions of Josh Naylor and Eugenio Suarez.
Predictions for Blue Jays vs. Mariners Game 5
The Blue Jays offence will enter this matchup with plenty of confidence after two strong performances, and should be well-situated to stay hot versus Miller. They hit Miller quite respectably in their previous matchup despite the lack of results, and it wouldn’t be surprising to see them find more success as they get another look at him in short order.
Gausman has been one of the best pitchers in baseball in the back half of the season, and has remained in strong form in pitching to a 2.38 ERA this postseason. Though the Mariners offence has the upside for better, their lineup really has not been overly impressive this postseason, relying quite heavily on timely hitting to find results.
The Blue Jays should have a good chance to get off to an early lead in the Gausman vs. Miller innings of this matchup.
Backing Miller to allow over 1.5 earned runs at -120 is a solid option for bettors, but I see more value in backing Miller to allow over 1.5 ER and the Blue Jays to win the first three innings at a long price of +190, in a game where Miller holds a betting total of just 11.5 outs.
Best Bet: Bryce Miller Over 1.5 Earned Runs/Blue Jays to win First Three Innings +190 (bet365, play to +180)
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