The Cubs will play the Mariners on Saturday, March 21st, 2026. Your timezone's first pitch time is 9:10 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 Cubs at Mariners Odds
| Underdog Chicago Cubs | Favorite Seattle Mariners |
|---|---|
| Over | Under |
|---|---|
| Underdog Chicago Cubs | Favorite Seattle Mariners |
|---|---|
Matchup Odds FAQs
The Seattle Mariners are the -165 moneyline favorite at BetMGM and the Chicago Cubs are the +140 moneyline underdog at BetMGM.
The best over line is 11.5 -110 runs at BetMGM, which means you risk $110 to win $100 betting the over. The best under line is 11.5 -110 runs at BetMGM, and that means you risk $110 to win $100 betting the under.
The Seattle Mariners are -1.5 +110 run line favorites at BetMGM, while the Chicago Cubs are +1.5 -130 run line underdogs at BetMGM.
MLB Odds Example
|
Game |
 BetMGMBet |
|---|---|
Cubs
Mariners
3/21/26 9:10pm EDT | +140-165 |
- Chicago Cubs bettors risk $100 to win $140 at +140 odds. The implied probability for Chicago Cubs is 41.67%.
- Seattle Mariners bettors risk $100 to win $60.61 at -165 odds. The implied probability for Seattle Mariners is 62.26%.
Chicago Cubs at Seattle Mariners Prop Bets
| BetMGM Bet |
|
|---|---|
Cubs
Mariners
3/21/26 9:10pm EDT | Pending BetMGM |
Chicago Cubs & Seattle Mariners 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.
Chicago Cubs World Series Odds|
Team | BetMGM |
|---|---|
| Cubs | +1000 Bet |
|
Team | BetMGM |
|---|---|
| Mariners | +1300 Bet |
Chicago Cubs & Seattle Mariners 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago Cubs | 14 | 9 | 0.609 | +2.0 | 9-5 | 5-4 | 124 | 87 | +37 | W7 | 8-2 |
| Seattle Mariners | 10 | 15 | 0.400 | +7.0 | 9-7 | 1-8 | 96 | 95 | +1 | L2 | 4-6 |
How to Bet on the Game
Time needed: 4 minutes.
How to Bet on the Chicago Cubs vs Seattle Mariners 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 Saturday, March 21st, 2026 at 9:10 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 Chicago Cubs vs Seattle Mariners Game.
Navigate to the sportsbook's MLB page. Next, look for live or upcoming matchups. Select the Chicago Cubs vs Seattle Mariners 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 March 21, 2026 MLB Games
- Philadelphia Phillies vs Baltimore Orioles
- Atlanta Braves vs Boston Red Sox
- New York Yankees vs Detroit Tigers
- Toronto Blue Jays vs Pittsburgh Pirates
- Miami Marlins vs St. Louis Cardinals
- Minnesota Twins vs Tampa Bay Rays
- Oakland Athletics vs Los Angeles Dodgers
- Colorado Rockies vs Kansas City Royals
- Cleveland Guardians vs San Francisco Giants
- Texas Rangers vs Arizona Diamondbacks
- San Diego Padres vs Milwaukee Brewers
- Chicago White Sox vs Cincinnati Reds