The Mariners’ pitching staff has been the most successful in MLB history at throwing first-pitch strikes over the last two seasons.

The Mariners’ pitching staff has been the most successful in MLB history at throwing first-pitch strikes over the last two seasons.

For a major league pitcher, the numbers paint a clear picture: throw a first-pitch strike and good things will (almost always) happen.

That, for years, has been the backbone of the Mariners’ pitching philosophy.

Over the past two seasons, the Mariners have been more successful than any pitching staff in MLB history at throwing first-pitch strikes — one reason, they believe, their starting rotation has been as dominant as any in the sport over the past two decades.

And the youngest member of that rotation, Bryan Woo, is enjoying a breakthrough season in part because he’s throwing first-pitch strikes at a historic rate.

Armed with a “rising” fastball that continues to baffle hitters, Woo acknowledged that his confidence has risen to an all-time high.

And that confidence is evident in his aggressive approach to challenge hitters more than any other pitcher.

Through his 19 starts this season, the 24-year-old right-hander has thrown a strike on 73.8% of his first pitches. Over a full season, that’s the highest first-pitch strike rate of any MLB pitcher — starter or reliever — in FanGraphs’ database, going back to 2002.

Why is that relevant?

Across MLB, data show that the vast majority of the time — roughly 92% — a first-pitch strike leads to a positive outcome for the pitcher: either an 0-1 count or an out.

“I think that’s the one place where analytics and numbers can really come in handy. They just show you straight facts,” Woo said. “When you throw strike one, the numbers are going to be in your favor.”

That’s the consistent — and persistent — messaging from Mariners pitching coaches and analysts from Day 1 when pitchers arrive in the organization. The goal is simple: get ahead and get ‘em out.

“When you use as much as we do, and when you talk about it as much as we do, why would you not [do it]?” Woo said.

Eventually, strike-throwing starts to become part of the DNA of a Mariners pitcher.

In 2023, the Mariners pitching staff set an MLB record with a 64.5% first-pitch strike rate.

The Mariners are on track to break that record again, with a 65.6% rate this season.

Woo’s aggressiveness goes beyond just the first pitch.

He also leads all MLB pitchers this season in overall strike percentage at 51.3% — the highest rate for any pitcher since 2017. (Across MLB, pitchers are throwing strikes on 42.3% of their pitches this season.)

The Mariners’ George Kirby led MLB in overall strike percentage (48.2%) in 2023, and Logan Gilbert (47%) and Bryce Miller (46.4%) also ranked in the top five.

On top of first-pitch strikes, the Mariners pitching-development program emphasizes winning the 1-1 count too — again, the numbers overwhelmingly favor the pitcher when they throw a strike in that count — and Woo said the 0-0 and 1-1 count percentages are the two things he consistently checks in the “Shove Report” he receives after each of his starts.

Gilbert, Kirby, Miller and Woo are all homegrown and they’re all elite strike-throwers.

Woo has just taken strike-throwing to another level.

Woo’s strike rate in 1-1 counts is 74.0% — right in line with his first-pitch strike rate and a significant improvement from his 1-1 rate as a rookie last season (64.4%).

“There’s no bias to [the data],” Woo said. “I know that if I’m doing those things consistently well over the course of the year that I’m probably going to have pretty consistent success.”

Woo had one of the best starts of his career in a victory over the San Diego Padres on Wednesday night, retiring the first 19 batters he faced.

Padres star Fernando Tatis Jr. broke up Woo’s perfect-game bid with a seventh-inning homer, turning on a 95-mph inside fastball. It was the rare at-bat in which Woo had fallen behind 1-0 to a hitter.

Even so, Tatis was quite complimentary of Woo after the game.

“His ball was rising on a level I haven’t seen much,” Tatis told reporters. “The guy has really good stuff. He was pounding the zone. His fastball was really alive and he was making good pitches all the way from the beginning.”

Dodgers star Mookie Betts similarly raved about Woo after facing him for the first time a couple weeks ago.

And the reactions from the hitters has added to Woo’s growing confidence.

“It’s really cool to hear from guys with stature like that,” said Woo, 8-2 with a 2.38 ERA in 105.2 innings this season. “But I think [the growth] is really just incremental. If you continue to do the things that really matter and try to get better every day, like, that’s where it really comes from — that’s where you really get better. So I think it’s just kind of a product of doing the little things every day.”