Cal Raleigh has the perfect summary of Bryan Woo's dominance for Mariners

The Seattle Mariners are about to play their most important regular-season series in years, but there's at least one good reason to not feel nervous about it. Heck, it's a powerful enough reason that you might even feel optimistic.

Bryan Woo is starting the opener.

This hardly guarantees that the Mariners will get the better of the Houston Astros in the first of three at Daikin Park on Friday, much less either of the next two games. And Woo has indeed drawn a tough assignment, as opposing him will be Hunter Brown, whose 2.27 ERA is the third-lowest among qualified starters.

Woo is as solid as solid can be, however. The 25-year-old righty has gone at least six innings in all but two of his 29 starts, and he's rocking a 3.02 ERA and 5.5 strikeout-to-walk ratio. The Mariners have won six of his last eight starts.

Cal Raleigh summed up what makes Bryan Woo so special as the Mariners' ace

All of this — plus an All-Star nod in July — has helped put Woo on the national radar throughout 2025. It's a truly remarkable rise for a guy who was a sixth-round draft pick just four years ago.

Most Mariners fans probably at least know the broad strokes of the story, but the latest from Jordan Shusterman of Yahoo Sports on Woo's ascent is worth a read anyway. He goes deep on how the Mariners scouted Woo when he was at Cal Poly, as well as on how they developed his arsenal and approach to be of ace-caliber quality.

It's when Shusterman gets into Woo's effect on opposing hitters that the really good quotes come out, including this one from Cal Raleigh on how his fastball plays: “He has some good deception in the sense of, you know, he's so smooth, and it comes out so easy that you don't think it would get on you like that, and it does. You can just tell by swings — guys feel like they're seeing it, and they're not. It's created a lot of angry hitters.”

Though this is specifically in reference to Woo's four-seam fastball, he also attacks hitters with a sinker. Put together, the two pitches make up 73.0 percent of his offerings.

Raleigh's line about Woo creating angry hitters says it all about how the four-seamer and sinker frustrate the heck out of the opposition. Those two pitches should be hittable. His fastball velocity is solid but not extraordinary at an average of 95.6 mph, and he goes right at hitters in the strike zone.

But as these stats show, it's not that simple:

• Fastballs in Strike Zone: 1,165 (1st in MLB)
• Whiffs on Fastballs in Strike Zone: 164 (3rd in MLB)
• Hits off Fastballs in Strike Zone: 84 (T-11th in MLB)
• Run Value on Fastballs in Strike Zone: 42 (1st in MLB)

For further reference, hitters are batting .281 against fastballs in the strike zone, compared to .224 against all other pitches. Against Woo's in-zone fastballs, they're batting just .218. His standard is thus better than the average pitcher's best.

Lest anyone get overly confident that Woo will come through for the Mariners on Friday, the Astros are one of the better fastball-hitting teams in MLB. Their .282 average against four-seamers and sinkers is the best of any team, even if it only comes with a .445 slugging percentage that ranks seventh.

As Woo has demonstrated, however, the ability to hit the fastball doesn't tend to matter against him. If that remains the case, he's going to add quite a few more angry hitters to his collection on Friday.