The Mariners will play the Astros on Sunday, September 21st, 2025. Your timezone's first pitch time is 7:10 pm EDT. Check local listings or your nearest streaming app for coverage.
Learn more about MLB Betting with our handy tutorial and guide. We explain money line, total and run line bets. Plus, a great discussion about exotic bets like MLB Baseball parlays and props.
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Table of Contents
- Best Odds
- Interactive Odds Example
- Prop Bets
- Team Futures Odds
- Team Pages
- Team Standings
- Other Games Today
Best Mariners at Astros Odds
| Underdog Houston Astros | Favorite Seattle Mariners |
|---|---|
| Over | Under |
|---|---|
| Underdog Houston Astros | Favorite Seattle Mariners |
|---|---|
Matchup Odds FAQs
The Seattle Mariners are the -145 moneyline favorite at BetMGM and the Houston Astros are the +120 moneyline underdog at BetMGM.
The best over line is 8 -115 runs at BetMGM, which means you risk $115 to win $100 betting the over. The best under line is 8 -105 runs at BetMGM, and that means you risk $105 to win $100 betting the under.
The Seattle Mariners are -1.5 +120 run line favorites at BetMGM, while the Houston Astros are +1.5 -145 run line underdogs at BetMGM.
MLB Odds Example
|
Game |
 BetMGMBet |
|---|---|
Mariners
Astros
9/21/25 7:10pm EDT | -145+120 |
- Houston Astros bettors risk $100 to win $120 at +120 odds. The implied probability for Houston Astros is 45.45%.
- Seattle Mariners bettors risk $100 to win $68.97 at -145 odds. The implied probability for Seattle Mariners is 59.18%.
Seattle Mariners at Houston Astros Prop Bets
| BetMGM Bet |
|
|---|---|
Mariners
Astros
First Team to Score
9/21/25 7:10pm EDT | -190+145Bet |
Mariners
Astros
Tie
1st Inning Winner
9/21/25 7:10pm EDT | +260+350-140Bet |
Mariners
Astros
Tie
First 3 Innings Winner
9/21/25 7:10pm EDT | +115+175+280Bet |
Mariners
Astros
To Extra Innings
9/21/25 7:10pm EDT | Yes +725No -1200Bet |
| BetMGM | |
Mariners
Astros
1st Team to Score Will Win
9/21/25 7:10pm EDT | Yes -250No +190Bet |
Astros
Total Runs
SEA at HOU 9/21/25 7:10pm EDT | 3.5 o -1103.5 u -115Bet |
Mariners
Total Runs
SEA at HOU 9/21/25 7:10pm EDT | 4.5 o -1024.5 u -130Bet |
Jason Alexander
Strikeouts Thrown
SEA at HOU 9/21/25 7:10pm EDT | 4.5 o +1054.5 u -135Bet |
| BetMGM | |
Logan Gilbert
Strikeouts Thrown
SEA at HOU 9/21/25 7:10pm EDT | 5.5 o -1355.5 u +105Bet |
Seattle Mariners & Houston Astros Futures Odds
Latest World Series odds, if available, for each team. Review odds for other teams and learn how to bet on the tournament. See past Championship results and learn how to bet World Series teasers, props and parlays.
Seattle Mariners World Series Odds|
Team | BetMGM |
|---|---|
| Mariners | +180 Bet |
No World Series TM Houston Astros YR: futures available
Seattle Mariners & Houston Astros Team Pages
Review each team's season win total odds, futures odds, betting bonuses and other valuable information on our exclusive team betting odds pages. Team betting odds and stats update throughout the season:
Team Standings
| Team | W | L | Pct | GB | Home | Away | RS | RA | Diff | Strk | L10 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| x - Seattle Mariners | 90 | 72 | 0.556 | +7.0 | 51-30 | 39-42 | 766 | 694 | +72 | L3 | 7-3 |
| e - Houston Astros | 87 | 75 | 0.537 | +10.0 | 46-35 | 41-40 | 686 | 665 | +21 | W2 | 4-6 |
How to Bet on the Game
Time needed: 4 minutes.
How to Bet on the Seattle Mariners vs Houston Astros MLB Game
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Open a new sports betting account before game time.
Review our list of sports betting sites. Open a new account before the game starts on Sunday, September 21st, 2025 at 7:10 pm EDT, making sure to enter all your personal details correctly. Don't forget to add your bonus code.
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Visit the sportsbook’s cashier, banking, or deposit page.
Navigate to the sportsbook's deposit page. Use your Visa card or MasterCard, or deposit with a bank transfer, or other methods like Paypal.
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Tap to the sportsbook's MLB page, look for the Seattle Mariners vs Houston Astros Game.
Navigate to the sportsbook's MLB page. Next, look for live or upcoming matchups. Select the Seattle Mariners vs Houston Astros Game.
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Choose your bet and place a wager.
Choose your bet and then use the funds you deposited to place a wager. The sportsbook will pay your winnings or deduct a losing wager from your account balance after the game.
Other September 21, 2025 MLB Games
- New York Yankees vs Baltimore Orioles
- Oakland Athletics vs Pittsburgh Pirates
- Atlanta Braves vs Detroit Tigers
- Washington Nationals vs New York Mets
- Chicago Cubs vs Cincinnati Reds
- San Diego Padres vs Chicago White Sox
- Cleveland Guardians vs Minnesota Twins
- Toronto Blue Jays vs Kansas City Royals
- Milwaukee Brewers vs St. Louis Cardinals
- Miami Marlins vs Texas Rangers
- Los Angeles Angels vs Colorado Rockies
- San Francisco Giants vs Los Angeles Dodgers
- Philadelphia Phillies vs Arizona Diamondbacks
- Boston Red Sox vs Tampa Bay Rays