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

Odds updated as of 9:12 p.m.

In MLB action on Friday, the Seattle Mariners take on the Chicago Cubs.

We've got you covered, in terms of the most important info regarding this matchup before you take a look at the 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: (+100)
• Spread: SEA: +1.5 (-192) | CHC: -1.5 (+158)
• Total: 7.5 -- Over: (-124) | Under: (+102)

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's team is 8-15-0 against the spread this season in his starts. Hancock's team has a record of 8-9 this season when he starts and they are the favorite on the moneyline. The Cubs are 9-5-0 against the spread when Boyd starts. The Cubs have a 1-2 record in Boyd's three starts this season when they were the moneyline underdog.

Mariners vs Cubs Prediction & Pick

All MLB win probability predictions and picks are according to numberFire.
Prediction: Cubs win (50.2%)

Mariners vs Cubs Moneyline

• Chicago is a +100 underdog on the moneyline, while Seattle is a -108 favorite at home.

Mariners vs Cubs Spread

• The Cubs are 1.5-run favorites against the spread for this matchup with the Mariners. The Cubs are +158 to cover, while the Mariners are -192 to cover as a 1.5-run underdog on the runline.

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 -124 and the under at +102.

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

Mariners vs Cubs Betting Trends

• The Mariners have been victorious in 49, or 49.5%, of the 99 contests they have been chosen as favorites in this season.
• This year Seattle has won 50 of 100 games when listed as at least -108 on the moneyline.
• Contests with the Mariners have gone over the total set by sportsbooks in 63 of 127 chances 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 underdog on the moneyline this season (56.8%).
• Chicago has a 14-13 record (winning 51.9% of its games) when it has played as a moneyline underdog of +100 or longer.
• The Cubs have had an over/under set by oddsmakers 123 times, and have combined with opponents to go over the total in 66 of those games (66-57-0).
• The Cubs have a 61-62-0 record ATS this season (covering 49.6% of the time).

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 is 38th in batting average, 21st in on-base percentage, and 47th in slugging among all qualifying hitters in MLB.
• Josh Naylor leads Seattle in slugging percentage (.371) thanks to 28 extra-base hits. He's batting .268 with an on-base percentage of .330.
• Among qualifying hitters, his batting average ranks him 46th, his on-base percentage 77th, 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 racked up 136 hits with a .378 on-base percentage and a .550 slugging percentage, all club-highs for the Cubs. He's batting .279.
• Including all qualified players in MLB, his batting average puts him 28th, his on-base percentage is 11th, and he is third in slugging.
• Alex Bregman is hitting .255 with 24 doubles, a triple, 16 home runs and 63 walks. He's slugging .404 with an on-base percentage of .345.
• His batting average is 74th among all qualified players, his on-base percentage ranks 53rd, and he is 92nd in slugging.
• Nico Hoerner has 26 doubles, a triple, seven home runs and 40 walks while batting .264.
• Seiya Suzuki has 24 doubles, 22 home runs and 58 walks while batting .268.

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