Betting Trends: Toronto Blue Jays vs Seattle Mariners

The stage is set for betting trends and betting stats analysis in the MLB showdown between the Toronto Blue Jays vs Seattle Mariners on October 16, 2025 at T-Mobile Park in Seattle, WA, airing on Fox Sports 1. After their last matchup on October 15th, when the Blue Jays dominated the Mariners 13-4, both clubs are searching for momentum this Game 4.

Seattle will hand the ball to RHP Luis Castillo, who enters with a pristine 0.0 ERA and 0.8333 WHIP over one appearance this series. Castillo has excelled against right-handed hitters (.190 average) while holding lefties to a .250 clip, pairing an 11.1 K/9 strikeout rate with a 3.50 SIERA. The Blue Jays counter with RHP Max Scherzer, a veteran battling a 5.188 ERA and 1.2941 WHIP. Scherzer owns a .240 mark versus lefties and .220 against righties, delivering a 10.2 K/9 rate and a 3.90 SIERA. These splits suggest the Mariners’ lineup advantage against elite right-handers, tipping the spread in Seattle's favor.

Toronto enters with a 98-71 SU record and a 93-76 ATS mark, featuring MVP candidate Vladimir Guerrero Jr. and power arm Chris Bassitt. Bo Bichette and Ty France are sidelined, creating lineup gaps for Alejandro Kirk and Daulton Varsho. The Mariners, 95-75 SU and 75-95 ATS, lean on Julio Rodríguez and J.P. Crawford for offense. You can review home and away trends on our MLB standings page.

The moneyline sits at -135 for Seattle and +115 for Toronto, with the Mariners favored by 1.5 (-158) and the total set at 7.5 runs. Seattle’s dominant pitching and favorable park factors support an Under lean, while the spread offers value on the home side. Seattle’s best moneyline is -135 at Caesars, and Toronto’s +115 is also available at Caesars. Ready to bet smarter? Start your OddsTrader Turbo subscription now to access real-time odds and capitalize on the edge.