The Athletics vs Seattle Mariners Predictions, Odds and Picks for Today, 04/20/26

I favor the under on the posted game total in Monday’s matchup between the Athletics and the Seattle Mariners. Seattle will play host for this divisional series as they look to improve upon their 10-13 record. The Athletics enter play at 11-11 with their offense having carried the load so far. Entering the season Seattle had higher hopes and aspirations, and they are still favored in this matchup despite a slow start. I am instead focusing on the total in this matchup, however, as I find that to be the larger edge in this game.

Emerson Hancock is the scheduled starter for the Mariners as he looks to make his 5th start of the season. Hancock has broken out so far in 2026 with a 2.28 ERA across his first 23.2 innings of work. He has pitched efficiently with just 4 walks in that span, but his strikeout production is the real story with 25 Ks so far. Hancock has not been a strikeout pitcher in the past but if he can remain around a strikeout per inning this season we could see a true breakout. His 2.80 xERA and 2.75 FIP support his success to this point, and I expect another strong start today.

J.T. Ginn is set to start this game for the Athletics. Ginn did walk 4 batters in his last outing across 5.1 innings of work, but he was otherwise sharp in that outing. He got experience in this rotation last season, tossing 90.1 innings after 34 innings with the club the season prior. Ginn doesn’t have overpowering stuff, but he has done an exceptional job so far at limiting hard contact and keeping the ball on the ground. His baseball savant page has dark red circles littered across his sheet due to this quality metrics. His 3.31 ERA is backed by a 3.05 xERA and I expect the under to hit in Game 1 of this series.

The Athletics vs Seattle Mariners prediction: Under 8 (-105) available at time of publishing. Playable at that number.

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