Houston (56-40) vs Seattle (51-45)
July 18, 2025 at 10:10 PM EDT
The Line: Betting Odds: Seattle -135 / Houston +115 — Over/Under: +7.5
The Houston Astros are visiting the Seattle Mariners on Friday, July 18th at the T-Mobile Park in the opening game of this series. We will look at this from a betting perspective and determine the best bets for this game. Here’s a Houston Astros vs Seattle Mariners Prediction. We will examine:
The Seattle Mariners’ recent form and player performance
The Houston Astros’ recent form and player performance
Recent betting trends and streaks involving the Seattle Mariners
Recent betting trends and streaks involving the Houston Astros
Recent betting trends in games played between the Houston Astros vs Seattle Mariners
A summary that ties it all together and produces a favorable betting outcome for the Houston Astros vs Seattle Mariners game
Seattle Mariners Preview
The Seattle Mariners have a 51-45 record this season and are sitting in second place in the AL West. The Mariners have a 25-21 home record and 54-38 in over/under. They are coming off an 8-4 road victory over the Tigers and have three consecutive wins. Over is 6-0 in their last 6 games, and they are playing the Brewers and the Angels next.
The Mariners have a .250 batting average this season.a 326 OBP, and a .418 Slugging percentage. Seattle’s pitching staff has a 3.89 ERA and 1.26 WHIP. J.P. Crawford leads the Mariners in hits with 100 and is the team’s best hitter with a .290 batting average. Cal Raleigh leads the team both in RBI with 82 and in home runs with 38.
Luis Castillo (R) is the projected starting pitcher for the Mariners, and he has a 6-5 record, a 3.41 ERA, and 1.24 WHIP.
Houston Astros Preview
The Houston Astros have a 56-40 record this season and are sitting in first place in the AL West. The Astros have a 23-21 road record and 42-51 in over/under. They are coming off a 1-5 home defeat by the Rangers, and are 1-5 in their last 6 games. Over is 7-3 in their last 10 games, and they are playing the Diamondbacks and the Athletics next.
The Astros have a .258 batting average this season, a .323 OBP and a .411 slugging percentage. Houston’s pitching staff has a 3.61 ERA and 1.16 WHIP. Jeremy Pena leads the Astros with 102 hits and he is the team’s best hitter, with a .322 batting average. Jose Altuve leads the team in RBI with 52, while Isaac Paredes adds a team-high 19 home runs.
Brandon Walter (L) is the projected starter for the Astros, and he has a 1-2 record, 3.98 ERA and 1.01 WHIP.
Why the Seattle Mariners will win
The Mariners have won each of their last six home games against AL West opponents.
The Astros have lost five of their last six games.
The Astros have failed to cover the run line in each of their last 10 games against American League opponents.
The Mariners have covered the run line in each of their last six home games against AL West opponents.
The Astros have trailed after 5 innings in four of their last five games.
The Astros have lost the first inning in three of their last four night games against American League opponents.
The Mariners have led after 3 innings in each of their last five home games against AL West opponents.
Why the Houston Astros will win
The Astros have won each of their last eight games as underdogs against American League opponents following a loss.
The Mariners have lost each of their last six games as favorites against the Astros following a road win.
The Astros have covered the run line in each of their last 14 games as underdogs against American League opponents following a loss.
The Mariners have failed to cover the run line in each of their last eight games as favorites against the Astros following a road win.
The Astros have led after 5 innings in four of their last five games against the Mariners.
The Astros have led after 3 innings in each of their last four night games against opponents that held a winning record.
Total Runs Facts
Each of the Mariners’ last six games have gone OVER the total runs line.
Six of the Astros’ last seven night games against AL West opponents have gone OVER the total runs line.
The ‘Inning 1 UNDER 0.5 runs’ market has hit in each of the Astros’ last eight games at T-Mobile Park.
The ‘Inning 1 UNDER 0.5 runs’ market has hit in each of the last five night games between the Astros and Mariners at T-Mobile Park.
Matchup/League Facts
The Mariners rank 28th in the league for triples this season (5).
The Mariners are one of only three teams in the league to rank top 10 in both steals and home runs this season.
The Astros rank 1st in the league for batting average this season (.258).
The Astros rank 1st in the league for strikeouts this season (930).
Houston Astros vs Seattle Mariners Prediction
The Astros are 3-1 in their last 4 overall meetings against the Mariners, but both teams are tied 3-3 wins this season. The Mariners won their previous series in Seattle against the Astros this season by 2-1 wins. Under is 3-0 in their last 3 meetings. In this Houston AstrosvsSeattle MarinersPrediction, the Marinersare coming as -135 home favorites. The Astros have a better record, and both teams have similar home/away splits. Castillo for the Mariners is by far the better option on the mound in this matchup, as he has a 2.29 home ERA, while Walter for the Astros has a 5.73 road ERA. Castillo’s previous home start against the Astros this season was a shutout, so I expect them to dominate at home again. Take the Seattle Mariners to get the job done at home today.