Incredible stat shows M’s success owed more to Bryan Woo than you’d think

Bryan Woo has clearly been the Seattle Mariners’ best starting pitcher this year. But as valuable as he’s been on his days to pitch, his impact is being felt beyond that.

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ESPN’s Paul Hembekides unearthed an incredible stat related to Woo this week that highlights just how much of the Mariners’ success is owed to the first-time All-Star right-hander.

On the Baseball Tonight podcast with longtime ESPN MLB insider Buster Olney, “Hembo” made the case for Woo to be the starter in Game 1 of the playoffs for the Mariners, who currently own the American League’s third wild card spot with just over two weeks left in the regular season.

His reason has a lot to do with how the Mariners’ pitching does after Woo’s turn in the rotation.

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The 25-year-old Woo ranks 10th in MLB this year with 175 2/3 innings, and he’s tied for second with 20 quality starts, which is any start of at least six innings pitched and no more than three earned runs allowed.

Woo, who is 13-7 with a 3.02 ERA and 0.95 WHIP in 28 starts this year, even set a Mariners record with the most consecutive starts of at least six innings pitched to begin a season, which was snapped at 25 on Aug. 27.

That length Woo has provided has shown up in the Mariners’ bullpen performance. We’ll let “Hembo” take it from here:

The Mariners as a staff collectively this year own a bullpen ERA of 3.83. That is a bullpen ERA that ranks 11th in Major League Baseball. In the games in which Bryan Woo has started, that number goes down to 3.62, so that is slightly better.

But most remarkably, what I did was look at the earned run average of the Mariners’ bullpen in the game immediately following every Bryan Woo start, and that number is 1.82.

The Mariners’ bullpen has pitched to a sub-2.00 ERA in a fifth of their games in large part because of the length that Bryan Woo is providing them.

Mariners bullpen ERA this season:

3.83 overall
3.62 in Bryan Woo starts
1.82 in game after Woo starts

Should Seattle reach the postseason, he should get the ball in Game 1. pic.twitter.com/ITvk3TXEvE

— Paul Hembekides (Hembo) (@PaulHembo) September 11, 2025

By the way, according to Lyle Goldstein of Seattle Sports’ Brock and Salk as well as the Marine Layer Podcast, Woo’s spot in the Mariners’ rotation is currently lined up for the Game 1 start in an American League Wild Card Series.

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