The first-place Seattle Mariners have the best pitching staff in the majors and, with five weeks left in the regular season, this staff is on pace to break the one pitching record the Mariners value most.
Distilled to its most basic form, the Mariners organizational pitching philosophy is this:
Throw strikes.
Distilled further, Mariners coaches preach one thing above all else with their pitchers:
Throw a first-pitch strike.
No pitching staff in baseball history has done that better than the Mariners are doing it right now.
Over a full season, the 2018 Los Angeles Dodgers have the record for first-pitch strike percentage at 64.2%, according to FanGraphs.
The 2023 Mariners sit at 64.4% through 130 games.
It's no coincidence that Mariners pitchers also lead MLB in fewest walks issued, giving up just 2.50 walks per nine innings this season.
"We're emphatic about it," manager Scott Servais said Sunday afternoon, after the Mariners wrapped up a sweep of the Kansas City Royals to take sole possession of first place in the AL West at 74-56.
"You've got to throw strike one. We talk about it all the time and we don't back off, which is a credit to our coaching staff. Those guys understand how we're built, what our foundation is, and when you put our uniform on you better adhere to it or get in line and understand it. Because that's all you're going to hear every day, and it works. It works for us."
The Mariners aren't the only organization that prioritizes strike-throwing. The Tampa Bay Rays, who have built a reputation as the majors' best club at pitching development, had T-shirts made this year with "64.2%" on the front, a nod to the Dodgers' first-pitch strike record.
The Mariners have just taken that notion to another level. After the Mariners' 64.4% mark, the San Francisco Giants rank second at 63.4% this season.
Here's how often Seattle's regular starters (minimum 50 innings) are throwing first-pitch strikes:
George Kirby: 69.3%
Bryce Miller: 66.4%
Bryan Woo: 64.7%
Luis Castillo: 63.6%
Logan Gilbert: 62.6%
Marco Gonzales: 60.5%
Notable: Among all MLB starting pitchers (minimum 100 innings pitched), Kirby ranks third in first-pitch strikes and Miller ranks 18th. (Texas' Max Scherzer is first at 71.2% and Minnesota's Pablo Lopez is second at 69.3%.)
Here's the first-pitch strike rate for Seattle's top relief pitchers:
Gabe Speier: 77.9%
*Paul Sewald: 65.4%
Justin Topa: 63.6%
Matt Brash: 61.7%
Tayler Saucedo: 59.3%
Andres Munoz: 57.5%
(*Sewald traded to Arizona on July 31.)
Notable: Among all MLB pitchers who have thrown at least 40 innings, Speier's 77.9% ranks No. 1. The league average is right about 62%.
Kirby has issued a league-low 14 walks in 156.1 innings, and his 2.3% walk rate, if it holds, would be the lowest of any qualified starting pitcher since 2014.
And, yes, it helps that the Mariners have a starting pitcher in Kirby who is throwing strikes at a historic rate.
But it's more than just one pitcher and one pitch.
Castillo, the 30-year-old ace, might be the best example of the Mariners' philosophy.
Just two years ago, while pitching for the Reds, Castillo issued 75 walks in his 33 starts, the most in the National League that season. Two years before that, in 2019, he had the fourth-worst walk rate in all of baseball at 10.1%.
Here in his first full season with the Mariners, Castillo has issued 38 walks in 164.1 innings, lowering his walk rate to a career-low 5.8% and emerging as a bona fide Cy Young candidate. His 3.01 ERA leads Seattle's staff, which boasts a league-best 3.67 ERA overall.
"For me, confidence was the key," Castillo, through interpreter Freddy Llanos, said Sunday after throwing seven shutout innings in which he allowed only one hit and issued only one walk. "Having confidence in myself in having confidence in all the pitches that I throw."
