Mariners vs Blue Jays Prop Picks & Best Bets for ALCS Game 7

Player
Shane Bieber Over 4.5 strikeouts	-135
George Kirby Over 3.5 strikeouts	+120
Vladimir Guerrero Jr. Over 1.5 total bases	-110

Mariners vs Blue Jays player prop picks

Prop #1: Shane Bieber Over 4.5 strikeouts

-135 at BetMGM

As an analytical, data-driven bettor, it’s not usually my style to lean on intangibles, but in this case, I’m making an exception. I’ll put it simply: there’s just something about backing Shane Bieber in a spot like this.

Some aspects of this matchup are admittedly non-quantifiable. Bieber is a veteran who’s pitched in countless high-stakes games and won’t be rattled by the moment. That experience might matter most when it comes to strikeouts. Of course, confidence alone doesn’t cash tickets; the matchup still has to align.

Earlier in this series, Bieber struck out eight Seattle Mariners, his second-highest total of the postseason, and the underlying data supports it. 

Seattle’s high-variance, all-or-nothing approach has made it a frequent target for opposing strikeout props. Bieber’s breaking pitches — especially his slider — are key to that success. The pitch generated a 37% whiff rate, and the Mariners have consistently struggled against it all season. In a high-pressure elimination scenario, I expect that trend to continue.

I would confidently play this down to −156.

Prop #2: George Kirby Over 3.5 strikeouts

+120 at BetMGM

The main factor driving this price, much like with Bieber, is the expected leash George Kirby will have. During the regular season, you’d rarely see a number this low for him, which makes it worth handicapping just how “short” that leash might actually be. I’m inclined to believe it will be long enough to clear this number.

“He’s the guy that we want in that situation,” Seattle manager Dan Wilson said late Sunday. “He’s thrown the ball well, and it’s his spot.”

Now, confidence-boosting quotes from managers don’t always carry much weight without corresponding action, but Wilson’s belief seems genuine. He’s trusted Kirby to work through some tough, high-leverage situations this postseason against quality opponents.

From a Toronto Blue Jays perspective, there isn’t a flashing signal to back this. We know who they are by now: low strikeouts, consistent contact, and constant pressure on defenses. That’s their formula, and it's why the Jays are here. 

Still, Kirby’s elite swing-and-miss ability, ranking in the Top 10% league-wide in whiff rate, gives him a legitimate path to success even against that profile. With the pressure mounting, I expect him to repeat his earlier performance in this series when he went over this mark.

I project 4.56 strikeouts, so I simply can’t pass this up.

Prop #3: Vladimir Guerrero Jr. Over 1.5 total bases

-110 at BetMGM

Superstar. What else can you say about Vladimir Guerrero Jr.?

This postseason, he’s delivered in every way you’d want the face of your franchise to deliver. The slash line says it all: .462 / .532 / 1.000. It would be an injustice not to back him with everything on the line. I projected this number around -128, which only adds to the appeal.

I like this matchup against Kirby, too. It’s easy to see why when Guerrero went single, double, and homer in his three plate appearances against him earlier in this series. 

Like most strikeout pitchers, Kirby gives up a lot of hard contact when he doesn’t miss bats, ranking in the Bottom 21% of the league in that area. Early in his career, Guerrero’s higher whiff rate made that less of an issue, but he’s made significant strides in plate discipline, and it’s something Kirby has to respect. The pitch mix of four-seam fastball, slider, and sinker also aligns well for Guerrero’s profile.

Given his postseason form, I'll happily back this. 

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