San Francisco Giants vs Seattle Mariners Preview
Today's Starting Matchup
Today's starting pitching matchup features San Francisco Giants's Logan Webb (5-7, 3.86 ERA) against Seattle Mariners's Bryan Woo (7-6, 4.23 ERA).
Both starters carry similar ERAs, setting the stage for a potential pitchers' duel. WHIP: Logan Webb 1.16, Bryan Woo 1.07.
Advanced metrics: Logan Webb — FIP 3.44, K% 19.4%, 100.3 IP / Bryan Woo — FIP 3.05, K% 24.1%, 104.3 IP
Career H2H Analysis
Logan Webb owns a .143 career batting average against (3-for-21) vs. Seattle Mariners's top of the order — a strong sign for a quality outing.
Bryan Woo has struggled against San Francisco Giants's No. 5 hitter Heliot Ramos, allowing a .500 career average (3-for-6), including 1 HR.
Bryan Woo has a concerning .304 career BAA (7-for-23) vs. San Francisco Giants's top of the order — early damage is a real possibility.
Team Season Comparison
2026 season record: San Francisco Giants 42-55 (.433), Seattle Mariners 48-50 (.490).
Seattle Mariners holds the edge in the season standings, though San Francisco Giants can't be counted out based on head-to-head matchups.
Run differential: San Francisco Giants -57, Seattle Mariners +9. Both clubs are evenly matched in run production.
Recent form: San Francisco Giants on a 3-game win streak, Seattle Mariners on a 1-game losing streak.
Based on starting pitching, San Francisco Giants holds the edge.
Bullpen Analysis
San Francisco Giants bullpen: 13 relievers on the active roster. Key arms: Adrian Houser 4.95 ERA, 55K in 80.0IP, Caleb Kilian (Closer) 4.62 ERA, 48K in 39.0IP, Dylan Smith 3.55 ERA, 13K in 12.2IP.
Seattle Mariners bullpen: 13 relievers on the active roster. Key arms: Andrés Muñoz (Closer) 4.19 ERA, 51K in 34.1IP, Bryan Woo 4.23 ERA, 102K in 104.1IP, Bryce Miller 2.27 ERA, 71K in 63.1IP.
Win Probability
Projected win probability: San Francisco Giants 50% vs Seattle Mariners 50%
Factors: San Francisco Giants's starter owns the lower ERA, Seattle Mariners's home-field advantage. Of course, baseball's inherent randomness means actual results may differ.
Key Tactical Points
Workload comparison: Logan Webb averages 6.3 IP per start vs. Bryan Woo at 5.8 IP. Getting six-plus innings from the starter significantly eases the bullpen burden.
Bryan Woo has allowed 10 HR this season — a concern against a lineup with extra-base power.