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Chicago Cubs vs. Seattle Mariners prediction, pick for Friday 6/20/25

Chicago Cubs vs. Seattle Mariners prediction, pick for Friday 6/20/25

Published:

By: Dan Johnson

The Cubs (45-29) have been in steady form, winning three of their last four, and are firmly planted in second place in the NL Central, with a six-game lead over third-place Milwaukee. They are riding a strong home record, going 12-3 over their last 15 at Wrigley Field. Meanwhile, the Mariners (37-36) are barely holding onto relevance in the Wild Card race, having dropped seven of their last 10, including two straight on the road. With George Kirby (1-3, 5.96 ERA) starting for Seattle, and Matthew Boyd (6-3, 2.79 ERA) taking the mound for Chicago, there’s a sharp contrast in recent form that’s worth backing. Below, I’ve got my preview, prediction, and best bet for this Friday baseball game between the Cubs and the Mariners.

Here’s how I’ll play it. I’ll be pumping out these predictions for individual games all season, with plenty of coverage here on DraftKings Network. Follow my handle @dansby_edits for more betting plays.

Cubs vs. Mariners prediction, preview

The Cubs have dominated this matchup, winning five of the last six meetings, and with their superior lineup and home-field advantage, they’ll be a tough matchup for the Mariners.

The Cubs’ offense has been explosive, ranking second in the majors in runs per game (5.34), with their potent lineup backed by key figures like Pete Crow-Armstrong (20 HR, 60 RBIs) and Seiya Suzuki (18 HR, 61 RBIs). Crow-Armstrong continues to heat up like megadragon fire, and with his power-speed combo, he’s been a key asset to Chicago’s offensive surge. They’ve ranked fifth in both slugging percentage (.436) and home runs (99) this season. This should pose a problem for George Kirby, who’s been struggling with his command, allowing a 1.36 WHIP and five HRs in just 25.2 innings this season. The Mariners have ranked 14th in batting average (.242) and have been inconsistent offensively, especially on the road (1-7 SU in their last 8). That inconsistency, coupled with Kirby’s struggles, means the Cubs should have little trouble putting runs on the board, especially at home.

On the mound, Matthew Boyd has been a steady force, with a 2.79 ERA over 80.2 innings. His advanced stats back up his solid performance; he owns a 3.57 xERA and a 25.7% K-rate at Wrigley, and he’s been particularly effective in day games. Boyd has also been strong at home with a 2.25 ERA. Against a Mariners team that’s struggled on the road and ranks 27th in runs over the last 30 days, Boyd should be able to keep Seattle’s bats at bay. While the Mariners’ bullpen has been solid recently (0.66 ERA in their last 5 games), they’ve been prone to giving up runs in high-leverage situations, and with Seattle’s lineup struggling, Boyd should capitalize.

The key story here is Boyd. His control, with a 5.8 BB% and 73 strikeouts, makes him a nightmare for a Mariners lineup that strikes out at a 25.7% clip against lefties. Boyd’s ability to get batters to chase his slider while keeping the ball in the yard is critical. Conversely, Kirby’s struggles to locate his fastball, especially in hitter-friendly parks, make this a bad matchup for him. His 5.96 ERA and high HR rate do not bode well against a Cubs team that thrives on power, especially with the wind potentially blowing out at Wrigley. If Boyd stays in control, this game could get out of hand for Seattle.

Mariners vs. Cubs pick, best bet

The Cubs have been consistently covering the spread at home, especially against AL teams, with a 12-3 record in their last 15 at home. Meanwhile, the Mariners have struggled to cover the run line on the road, going 1-7 in their last eight road games. Additionally, the Cubs have shown strong form in the first five innings, winning 6 of their last 7 against AL West teams. With Boyd’s consistency and the Cubs’ offensive power, expect them to build a lead early and keep it throughout. Seattle’s struggles to generate consistent offense, combined with Boyd’s ability to shut down left-handed hitters, further solidify the Cubs as the play.

I’m locking in the Cubs to cover the runline. They’re the more reliable side, with a better offense, stronger pitching, and the home-field edge. Boyd’s performance at home against a struggling Seattle offense points to a comfortable win. The Cubs will take care of business and continue their strong home stretch, keeping their foot firmly on the gas.

Plus: Sammy’s home.

Best bet: Chicago Cubs -1.5 (+140) vs. Seattle Mariners

Sammy’s home!—tail it with me in the DKN Betting Group here!

Dan Johnson has been an editor, writer, and analyst for DraftKings and DraftKings Network since 2024. He’s previously held editorial posts at The Paris Review, Macmillan Publishers, Bedford/St. Martin’s Press, ASSIGNMENT Magazine, and FantasySixPack. You can find his various editorial work & writing (sports-related and non-) at all of the above.
Disclaimer

I am a promoter at DraftKings and am also an avid fan and user (my username is thegreatdansby9) and may sometimes play on my personal account in the games that I offer advice on. Although I have expressed my personal view on the games and strategies above, they do not necessarily reflect the view(s) of DraftKings and do not constitute a representation that any particular strategy will guarantee success. All customers should use their own skills and judgment in building lineups. I may also deploy different players and strategies than what I recommend above. I am not an employee of DraftKings and do not have access to any non-public information.