Mariners vs Cubs Prediction, Odds, Moneyline, Spread & Over/Under for Aug. 21

Odds updated as of 4:11 a.m.

Friday's slate in the MLB includes a matchup between the Seattle Mariners and the Chicago Cubs.

Here's everything you need to know before checking out today's MLB odds and spreads on FanDuel Sportsbook.

Mariners vs Cubs Game Info

• Seattle Mariners (60-68) vs. Chicago Cubs (74-54)
• Date: Friday, August 21, 2026
• Time: 10:10 p.m. ET
• Venue: T-Mobile Park -- Seattle, Washington
• Coverage: Mariners.TV and MARQ

Mariners vs Cubs Odds & Moneyline

• All MLB odds, betting lines and prop bets are available on FanDuel Sportsbook.
• Moneyline: SEA: (-108) | CHC: (-108)
• Spread: SEA: +1.5 (-184) | CHC: -1.5 (+152)
• Total: 7.5 -- Over: (-122) | Under: (+100)

Mariners vs Cubs Probable Starting Pitchers

Probable Pitchers: Emerson Hancock (Mariners) - 7-7, 3.30 ERA vs Matthew Boyd (Cubs) - 8-2, 4.02 ERA

The probable starters are Emerson Hancock (7-7) for the Mariners and Matthew Boyd (8-2) for the Cubs. Hancock and his team have a record of 8-15-0 against the spread when he starts. Hancock's team has a record of 8-9 this season when he starts and they are the favorite on the moneyline. When Boyd starts, the Cubs have gone 9-5-0 against the spread. The Cubs have been the underdog on the moneyline in three of Boyd's starts this season, and they went 1-2 in those games.

Mariners vs Cubs Prediction & Pick

All MLB win probability predictions and picks are according to numberFire.
Prediction: Cubs win (51.9%)

Mariners vs Cubs Moneyline

• Seattle is a -108 favorite on the moneyline, while Chicago is a -108 underdog on the road.

Mariners vs Cubs Spread

Mariners vs Cubs Over/Under

• The Mariners-Cubs game on Aug. 21 has been given an over/under of 7.5 runs. The over is set at -122 and the under at +100.

Bet on Seattle Mariners vs. Chicago Cubs on FanDuel today!

Mariners vs Cubs Betting Trends

• The Mariners have been favorites in 99 games this season and have come away with the win 49 times (49.5%) in those contests.
• Seattle has a record of 50-50 in contests when sportsbooks favor them by -108 or more on the moneyline.
• The Mariners and their opponents have gone over in 63 of their 127 games with a total set by sportsbooks this season.
• The Mariners are 45-82-0 against the spread in their 127 games with a line set by sportsbooks this season.
• The Cubs have won 21 of the 37 games they were the moneyline underdog this season (56.8%).
• When playing as a moneyline underdog with odds of -108 or longer, Chicago has gone 21-16 (56.8%).
• In the 123 games bookmakers have set an over/under for the Cubs, they have combined with opponents to go over the total 66 times (66-57-0).
• The Cubs have gone 61-62-0 ATS this season.

Mariners Player Leaders

• Randy Arozarena leads Seattle in total hits (121) this season while batting .272 with 44 extra-base hits. He has an on-base percentage of .366 and a slugging percentage of .449.
• He ranks 38th in batting average, 21st in on-base percentage, and 47th in slugging among qualified hitters in the majors.
• Josh Naylor has an OPS of .702, fueled by an OBP of .330 and a team-best slugging percentage of .371 this season. He's batting .268.
• Among qualifying hitters, his batting average ranks him 46th, his on-base percentage 76th, and his slugging percentage 119th.
• Julio Rodriguez has collected 116 base hits, an OBP of .317 and a slugging percentage of .416 this season.
• Cole Young has 15 home runs, 56 RBI and a batting average of .254 this season.

Cubs Player Leaders

• Pete Crow-Armstrong has an on-base percentage of .378, a slugging percentage of .550, and has 136 hits, all club-highs for the Cubs (while batting .279).
• Including all qualified players, he ranks 28th in batting average, while his on-base percentage is 11th and he is third in slugging.
• Alex Bregman is batting .255 with 24 doubles, a triple, 16 home runs and 63 walks. He's slugging .404 with an on-base percentage of .345.
• Including all qualifying hitters, he ranks 74th in batting average, 53rd in on-base percentage and 92nd in slugging percentage.
• Nico Hoerner is hitting .264 with 26 doubles, a triple, seven home runs and 40 walks.
• Seiya Suzuki has 24 doubles, 22 home runs and 58 walks while hitting .268.

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