The Mariners have a win total of 89.5 entering the 2026 season, according to the latest MLB win totals market at the BetMGM online sportsbook.
Mariners Over/Under Wins 2026
- Over 89.5 wins: -120
- Under 89.5 wins: +100
Mariners Win Total Prediction 2026
- Over 89.5 wins
Based on the latest MLB odds, I like the over on the Mariners’ win total of 89.5 ahead of the 2026 season.
The vibes are extremely high in Seattle right now. Not only have the Seattle Seahawks won the Super Bowl, but the Mariners enter the upcoming season as one of the best teams in baseball. They could be in store for a historic year.
Seattle has a stellar season in 2025, winning 90 games and its first American League West title since 2001. The Mariners came one win short of their first pennant in franchise history, losing to the Toronto Blue Jays in a seven-game thriller.
Compared to the Blue Jays, the Mariners didn’t make as many splashes in free agency. Their big offseason addition was trading for Brendan Donovan, a versatile player who can help stabilize the top of the lineup.
Honestly, it makes sense that the Mariners didn’t do much else this winter. Their roster is solid across the board.
Catcher Cal Raleigh is the headliner after a runner-up finish in the American League MVP race. He led the majors with 60 home runs and 125 RBIs. Julio Rodriguez is an overqualified running mate behind Raleigh, coming off a 5.7 fWAR season.
Seattle’s lineup has a league-average (or better) batter in every spot in the lineup. According to RosterResource at FanGraphs, the Mariners rank fifth in all of baseball for projected offensive WAR in 2026.
And yet, the Mariners’ pitching projects to be just as good.
Their pitching staff ranks sixth overall in projected WAR for the upcoming campaign. They finished third with a 15.8% K-BB% clip in 2025. Seattle has multiple starters capable of contending in the AL Cy Young race.
When you put this entire team together on paper, it’s easy to see why projections are forecasting another 90-win season. PECOTA projects 93.1 wins for the Mariners, which is more than eight games better than any other AL West team.
This is the best team in the American League.
Mariners Win Total History
(Data from Sports Odds History)
| Year | Win Total | Wins | Result |
|---|---|---|---|
| 2025 | 85.5 | 90 | Over |
| 2024 | 87.5 | 85 | Under |
| 2023 | 87.5 | 88 | Over |
| 2022 | 84.5 | 90 | Over |
| 2021 | 72.5 | 90 | Over |
| 2020 | 24.5 | 27 | Over |
| 2019 | 71.5 | 68 | Under |
| 2018 | 81.5 | 89 | Over |
| 2017 | 85.5 | 78 | Under |
| 2016 | 82.5 | 86 | Over |
| 2015 | 87.5 | 76 | Under |
| 2014 | 81 | 87 | Over |
| 2013 | 77.5 | 71 | Under |
| 2012 | 72 | 75 | Over |
| 2011 | 70 | 67 | Under |
| 2010 | 83.5 | 61 | Under |
| 2009 | 71.5 | 85 | Over |
| 2008 | 85 | 61 | Under |
| 2007 | 75.5 | 88 | Over |
| 2006 | 75.5 | 78 | Over |
| 2005 | 76 | 69 | Under |
| 2004 | 88.5 | 63 | Under |
| 2003 | 90 | 93 | Over |
| 2002 | 95.5 | 93 | Under |
| 2001 | 81.5 | 116 | Over |
| 2000 | 83.5 | 91 | Over |
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