Mariners vs Orioles Prediction, Odds, Moneyline, Spread & Over/Under for Aug. 12

Odds updated as of 6:14 p.m.

The MLB slate on Tuesday includes the Seattle Mariners facing the Baltimore Orioles.

Before you do any MLB betting on this game at FanDuel Sportsbook, here's what you need to know.

Mariners vs Orioles Game Info

• Seattle Mariners (66-53) vs. Baltimore Orioles (53-65)
• Date: Tuesday, August 12, 2025
• Time: 6:35 p.m. ET
• Venue: Oriole Park at Camden Yards -- Baltimore, Maryland
• Coverage: MASN and ROOT Sports NW

Mariners vs Orioles Odds & Moneyline

• All MLB odds, betting lines and prop bets are available on FanDuel Sportsbook.
• Moneyline: SEA: (-158) | BAL: (+134)
• Spread: SEA: -1.5 (+104) | BAL: +1.5 (-125)
• Total: 9 -- Over: (-118) | Under: (-104)

Mariners vs Orioles Probable Starting Pitchers

Probable Pitchers: George Kirby (Mariners) - 7-5, 4.04 ERA vs Dean Kremer (Orioles) - 8-8, 4.35 ERA

This contest's pitching matchup is set, as the Mariners will send George Kirby (7-5) to the mound, while Dean Kremer (8-8) will take the ball for the Orioles. When Kirby starts, his team is 6-7-0 against the spread this season. When Kirby starts a game and his team is the favorite on the moneyline, they have a record of 7-4. The Orioles have a 10-12-0 ATS record in Kremer's 22 starts that had a set spread. The Orioles have been the underdog on the moneyline in 11 of Kremer's starts this season, and they went 4-7 in those games.

Mariners vs Orioles Prediction & Pick

All MLB win probability predictions and picks are according to numberFire.
Prediction: Mariners win (58%)

Mariners vs Orioles Moneyline

• Baltimore is a +134 underdog on the moneyline, while Seattle is a -158 favorite on the road.

Mariners vs Orioles Spread

• The Mariners are at the Orioles and are favored by 1.5 runs (+104 to cover) on the runline. Baltimore is -125 to cover.

Mariners vs Orioles Over/Under

• The Mariners-Orioles contest on Aug. 12 has been given an over/under of 9 runs. The over is set at -118 and the under at -104.

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Mariners vs Orioles Betting Trends

• The Mariners have won in 46, or 57.5%, of the 80 contests they have been named as odds-on favorites in this year.
• This season Seattle has come away with a win 18 times in 26 chances when named as a favorite of at least -158 on the moneyline.
• The Mariners and their opponents have hit the over in 61 of their 116 games with a total set by oddsmakers this season.
• In 116 games with a line this season, the Mariners have a mark of 51-65-0 against the spread.
• The Orioles have won 45% of the games this season they were the moneyline underdog (27-33).
• In games it has played as a moneyline underdog with odds of +134 or longer, Baltimore has a record of 4-11 (26.7%).
• The Orioles have combined with opponents to hit the over on the total 50 times this season for a 50-62-4 record against the over/under.
• The Orioles have a 51-65-0 record ATS this season.

Mariners Player Leaders

• Cal Raleigh has 108 hits, which is best among Seattle hitters this season, while batting .247 with 61 extra-base hits. He has an on-base percentage of .354 and a slugging percentage of .593.
• Among qualified hitters in MLB, he is 106th in batting average, 37th in on-base percentage, and third in slugging.
• Raleigh has recorded a base hit in three straight games. During his last five outings he is hitting .200 with three home runs, three walks and 10 RBIs.
• Josh Naylor leads Seattle in OBP (.360) this season, fueled by 117 hits. He's batting .292 while slugging .464.
• Among qualified hitters, his batting average ranks him 13th, his on-base percentage 28th, and his slugging percentage 49th.
• Naylor heads into this game looking to extend his two-game hit streak. In his last five games he is hitting .500 with two doubles, three home runs, two walks and five RBIs.
• Julio Rodriguez leads Seattle in slugging percentage (.448) powered by 45 extra-base hits.
• Rodriguez has picked up a hit in two straight games. In his last five games he is batting .300 with three home runs, a walk and six RBIs.
• Eugenio Suarez has been key for Seattle with 100 hits, an OBP of .305 plus a slugging percentage of .544.

Orioles Player Leaders

• Gunnar Henderson has an on-base percentage of .353, a slugging percentage of .466, and has 118 hits, all club-bests for the Orioles (while batting .284).
• Including all the qualified players in the majors, he ranks 25th in batting average, 39th in on-base percentage and 48th in slugging percentage.
• Henderson hopes to build on a four-game hitting streak in this matchup. During his last five outings he is hitting .235 with a double, a home run, a walk and three RBIs.
• Jackson Holliday is batting .251 with 15 doubles, two triples, 14 home runs and 28 walks. He's slugging .391 with an on-base percentage of .303.
• His batting average is 95th among all qualified players, his on-base percentage ranks 127th, and he is 123rd in slugging.
• Adley Rutschman is hitting .235 with 16 doubles, a triple, nine home runs and 37 walks.
• Jordan Westburg is batting .266 with nine doubles, a triple, 14 home runs and 12 walks.

Mariners vs Orioles Head to Head

• 6/5/2025: 4-3 BAL (Favorite: Mariners, Spread: -1.5, Total: 7, Favorite Moneyline: -156, Underdog Moneyline: +132)
• 6/4/2025: 3-2 BAL (Favorite: Mariners, Spread: -1.5, Total: 8.5, Favorite Moneyline: -108, Underdog Moneyline: -108)
• 6/3/2025: 5-1 BAL (Favorite: Mariners, Spread: -1.5, Total: 7.5, Favorite Moneyline: -148, Underdog Moneyline: +126)
• 7/4/2024: 7-3 SEA (Favorite: Orioles, Spread: -1.5, Total: 7, Favorite Moneyline: -144, Underdog Moneyline: +122)
• 7/3/2024: 4-1 BAL (Favorite: Mariners, Spread: -1.5, Total: 7, Favorite Moneyline: -136, Underdog Moneyline: +116)
• 7/2/2024: 2-0 BAL (Favorite: Mariners, Spread: -1.5, Total: 7, Favorite Moneyline: -108, Underdog Moneyline: -108)
• 5/19/2024: 6-3 BAL (Favorite: Orioles, Spread: -1.5, Total: 7, Favorite Moneyline: -144, Underdog Moneyline: +122)
• 5/17/2024: 9-2 BAL (Favorite: Orioles, Spread: -1.5, Total: 8.5, Favorite Moneyline: -132, Underdog Moneyline: +112)
• 8/13/2023: 5-3 BAL (Favorite: Mariners, Spread: -1.5, Total: 8, Favorite Moneyline: -112, Underdog Moneyline: -104)
• 8/12/2023: 1-0 BAL (Favorite: Mariners, Spread: -1.5, Total: 8, Favorite Moneyline: -164, Underdog Moneyline: +138)

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