The Mariners made progress in 2019. The change wasn’t always perceptible in the big leagues, where the team finished last in the American League West and missed the playoffs for the 18th straight season, but there were flashes toward the end of the year of the good things that were happening down on the farm.

Take righthander Reggie McClain as an example. Seattle’s 13th-rounder out of Missouri in 2016 got hit around at high Class A Modesto for the first two full seasons of his career and returned there to begin 2019, albeit in the bullpen.

Something was different this time, and he suddenly found success. He made just six appearances at Modesto before moving to Double-A Arkansas, where he continued mowing down the competition. In 31.2 innings between the levels, McClain struck out 38 and walked just

four hitters.

McClain’s success continued at Triple-A Tacoma, which led to his first big league callup on Aug. 2. The first five pitches out of his hand that day came in at 94, 93, 94, 96 and 94 mph. And while that velocity might be standard-issue in the big leagues these days, it represented a stark change for a pitcher whose fastball typically sat in the 87-91 mph range in college and throughout his first few pro seasons.

So where did that extra velocity come from? It might have started in the 2018 offseason during a program designed to help Mariners pitching prospects make gains. The program, informally called "Gas Camp,” lived up to its name with McClain, who increased his average fastball velocity roughly six miles per hour from 2018 to 2019.

"It changes everything for a pitcher. It changes the mentality. It changes what he’s willing to throw in what counts, and it changes how he attacks the strike zone,” Mariners farm director Andy McKay said, explaining Gas Camp. "All of those things were happening really right in front of us.”

It would be unfair to expect everyone to add six miles of velocity to a fastball and then shoot up three levels in a season, but McClain’s season was far from the only success story among Mariners pitching prospects.

Seven of the 38 prospects who struck out more than 150 hitters in 2019 were part of Seattle’s system. Those seven ranged from the top prospects (Justin Dunn, Logan Gilbert) to the intriguing (Devin Sweet, Ljay Newsome) to potential late bloomers (Steven Moyers, Nabil Crismatt, Ian McKinney).

The Mariners’ Double-A Arkansas affiliate had a 4.16 strikeout-to-walk ratio that led all full-season minor league clubs. The rotation there at times included Gilbert, Newsome, Crismatt and Justus Sheffield, one of the key prizes the Mariners acquired from the Yankees for James Paxton.

High Class A Modesto pitchers recorded 1,479 strikeouts, the second-highest total in the minors.

The Mariners’ pitching boom even extended to their relief prospects. Righthander Sam Delaplane struck out an absurd 120 hitters in 68.2 innings. His strikeout rate of 45.8 percent led all minor leaguers with at least 60 innings; only one other pitcher—the Rangers’ Demarcus Evans—topped 40 percent.

It also marked the second straight season in which Delaplane, a 23rd-round selection in 2017 out of Eastern Michigan, had whiffed more than 100 hitters without making a start. Operating with a mid-90s fastball and a slider that have improved since turning pro, Delaplane stands as another one of Gas Camp’s biggest success stories.

"He understands where to throw his fastball and the movement he has on his slider,” said Nathan Bannister, a former Mariners farmhand who will spend 2020 as the pitching coach at low Class A West Virginia. "Once he gets the shape he wants on his fastball and the shape he wants on his slider, he knows when to use them and where to use them. He crushes that part of his game.”

Another of Gas Camp’s biggest wins has been the development of righthander Ljay Newsome, Seattle’s 26th-rounder in 2015 out of high school in Morganza, Md., who best exemplified the organization’s "Control The Zone” ethos. Among minor leaguers with more than 100 innings, Newsome threw strikes at the highest rate (72.6 percent), walked hitters at the lowest rate (2.7 percent) and, unsurprisingly, had the best ratio of strikeouts to walks (9.94). His 169 whiffs overall were tied for seventh in the minors.

After going through Gas Camp for the first time, Newsome showed increased velocity in the early portion of the season but didn’t maintain that bump for the entire year. He returned to the camp this offseason with the goal of throwing his fastball harder over the course of a full season.

Beyond throwing his fastball about two miles per hour harder, Newsome also came out of his first round of Gas Camp with a new approach to pitching as a whole. His arsenal and usage patterns were different, which led to a breakout year.

"(The velocity) was a huge piece, but this year was the first year Ljay threw exclusively four-seamers, and Ljay really used the zone and in a really spectacular, beautiful way,” Mariners pitching coordinator Max Weiner said. "His changeup got better by location strategies and his whole goal is how can he use both breaking balls better, which is a usage thing, and then working on the shape of the changeup.

"He really is the evolution of Gas Camp. He’s kind of the embodiment of what you would want, which is, you know, continue to work, understand where your limitations are and keep knocking one rung off that ladder of climbing up each step of the way. He’s very focused on what is right in front of his face. So he’s a great ambassador and he’s a tremendous leader.”

The nuts and bolts of Gas Camp vary depending on each pitcher’s needs but most involve some of the recent industry standards like long toss and weighted balls. One of the program’s biggest keys, however, is intent. Simply put, the Mariners believe that if their pitchers believe they can throw harder and consciously try to throw harder, then they will throw harder.

"It really just came down to: You can control your intent, you can control your velocity, right,” Weiner said while explaining part of the reason McClain, whom the Mariners lost on a waiver claim to the Phillies in the offseason, made such big gains from one season to the next. "There’s a huge mental component to this: just free yourself up. You’re a thoroughbred, go run, that kind of deal.”

With that in mind, part of the Gas Camp involves the run-and-gun throwing programs that tend to pop up on social media in videos that show pitchers throwing the daylights out of a ball with little regard to location. That might not work in a game, but it shows a pitcher that his body and arm might be capable of more than what it has produced to that point in his pro career.

Once pitchers see the heights they’re capable of, the next step is getting them to take the steps that got them there and translate it to the mound. Ideally, the Mariners want their pitchers to get to the point where they apply the lessons they’ve learned without having to think about it. In other words, they want the intent to become routine.

"You can also take the mental part of it, the subconscious, and that’s what you want to train. You want to train your movement patterns without thinking and just doing,” Bannister said. "We’re definitely trying to train our bodies and our arms and condition them in a way to be able to go on the mound, see a target and throw with intent through the target and strike people out.”

Harder fastballs, sharper offspeed pitches and smarter execution are all fantastic results. And if that’s all Gas Camp produced, the program would be considered a resounding success. But those are just the short-term goals. In the long view, the Mariners want what their prospects learn during their winter program to last a lifetime. Done correctly, they believe the camp can be the beginning of something that could help extend the best years of a pitcher’s career.

“The game is going to evolve and change to where these types of programs are going to not only be the norm,” McKay said, “but it’s also not a ‘I did it one year and it’s over.’”

Building velocity is one goal, but continuing to maintain that velocity is equally important, according to McKay.

“Even if you’re fortunate enough to stick around long enough, your body is probably not going to allow you to continue to build, but it’s going to slow down the regression.

“That’s really an important thing. People see, not only throughout the season, but each year of their career (that) velocity starts decreasing. I’m quite confident we can slow down that curve for pitchers who are willing to invest themselves not only in offseasons but also in altering things during the season a bit.”

Entering the 2018 season, Baseball America ranked the Mariners’ farm system as the worst in baseball. Two years later, the system has jumped all the way to No. 5 and houses five of the game’s Top 100 Prospects.

A great deal of that jump involves the additions and rapid rises of hitting prodigies Jarred Kelenic and Julio Rodriguez. Beyond those twin peaks, however, is a top-to-bottom pitching group that has made tremendous leaps over the last two seasons.

The pitchers in their system were talented to begin with, but buying into the Mariners’ organizational philosophy has helped turn their raw gifts into tangible results that have helped raise hopes for a brighter future coming soon in Seattle.

Mariners Mound Marvels

The Mariners overhauled their pitching development program following the 2018 season. It produced tangible results in 2019.

Seattle’s minor leaguers struck out 9.45 batters per nine innings last season, a rate that ranked fourth among all 30 organizations. Mariners pitchers walked 3.33 per nine innings, which was the second best rate.

Added together, the Mariners’ minor league pitchers boasted a best-in-baseball 2.84 strikeout-to-walk ratio. All 30 organizations are ranked by SO/BB ratio in the table below.