Seattle Mariners vs Houston Astros Prediction, Odds and Picks for Today, 05/11/26

The Seattle Mariners and Houston Astros open a new division series Monday evening with George Kirby (2.94 ERA, 1.10 WHIP) on the bump for the visitors while Peter Lambert (2.42 ERA, 1.16 WHIP) starts for Houston. Both pitchers have been solid, but you have to give the edge to Kirby — who sits 93rd percentile in pitching run value and 87th percentile with a 2.77 xERA. Both offenses have had success against right-handed pitching, ranking top-5 in wRC+ vs. RHP. However, there is a drastic dropoff when the bullpens come into play for Houston.

The Astros’ bullpen ranks dead last in MLB with a 6.05 combined ERA. On the contrary, Seattle sits top 10 with a 3.41 combined ERA and a well-rested unit entering this matchup. I’ll lean on Seattle’s pitching staff in this spot and take the Mariners to win the divisional matchup outright on the road.

Mariners vs Astros prediction: Seattle ML (-130) available at time of publishing. Playable to -140.

Skip the waitlist and sign up for Polymarket RIGHT NOW to get instant access and a $20 trading bonus! You can join Polymarket by clicking here and trade on our Mariners vs Astros predictions.