How a pair of Royals coaches helped add teeth to KC’s major-league pitching staff

The 2023 season over, Michael Wacha had an idea.

After 12 years as a pitcher in Major League Baseball, he wanted to add a slider to his repertoire ahead of the 2024 season. He just needed to come up with the right plan of action.

So, having signed with the Royals in December, the veteran right-hander reached out to KC pitching coaches Brian Sweeney and Zach Bove.

During spring training, the coaches examined the 32-year-old’s career numbers (he turned 33 in July) and considered Wacha’s baseline physical traits. They talked daily about correct pitching grips and various data as Wacha worked to incorporate the new-to-him pitch into his routine.

“We have been using a lot of that tech and stuff to see kind of the movement patterns that I have been getting on it,” Wacha said. “(We were) trying different grips to get the movement that we want. They were all on board with it as well. It was something that I’ve always been searching for.”

Wacha found a consistent grip on his slider earlier this season. He worked with Bove to debut the new grip in an April 23 game against the Toronto Blue Jays.

It produced positive results immediately.

Wacha allowed two earned runs in 4 1/3 innings that day. He threw the slider four times and it averaged 85.6 mph. His spin rate on the pitch increased 111 RPMs from his yearly average, per Baseball Savant.

And since that late-April start, Wacha has posted an 11-6 record and 3.19 earned-run average. He has recorded 83 strikeouts and limited opponents to a .239 batting average in that span. The slider has registered a 41.8% whiff rate and 11.4% putaway rate.

“It’s just a harder pitch,” Bove said. “Obviously, guys are focusing on the changeup and stuff like that. He had the kind of slow curveball. But it’s a harder pitch that kind of looks like a fastball out of the hand that can go down and away to righties and down in the (strike) zone to righties.”

Wacha, playing for his sixth big-league club after starting his career with a seven-year stint in St. Louis, credits Sweeney and Bove for their support in making any of this possible. Other Royals share similar stories.

The common thread: This coaching duo, deep into season two with manager Matt Quatraro, has been a driving force in the fast turnaround of the KC pitching staff.

A re-imagined approach

When the Royals hired Quatraro as their next manager ahead of the 2023 season, they set out to build a competitive roster based on versatility and analytics.

Quatraro built his coaching staff with such veterans as Vance Wilson (third base coach), Paul Hoover (bench coach) and Jose Alguacil (infield coach), among others. The additions of Sweeney and Bove were made to revamp the pitching staff with an eye on the future.

The Royals were in a self-proclaimed “season of evaluation” in 2023 after firing longtime executive Dayton Moore late in a dismal 2022 campaign. Throughout the year, they gave numerous prospects a look at the big-league level.

KC cycled through young pitchers, in particular, in hopes of getting a better sense of the talent in its farm system.

That gave Sweeney and Bove an opportunity to get to know those players and find ways to help them develop.

“I think the players have been super open since day one, so that just makes our job easier,” Bove said.

Sweeney, who previously spent five seasons with the Cleveland Guardians, utilized his wealth of experience to forge some important bonds. He pitched professionally for 18 seasons, including three in Japan with the Nippon Ham Fighters.

The players found that they could relate to Sweeney, and Sweeney to them. His veteran approach and ability to communicate created a clear space for open dialogue.

“They really truly care about the success we have,” veteran left-handed reliever Will Smith said. “They probably are the most happy when it goes right for us. I know the starters love them to death and the bullpen guys love them, too.”

With Sweeney hired, the Royals next tapped Bove as an assistant pitching coach. After spending four seasons with the Minnesota Twins, Bove brings a unique perspective steeped in deep understanding of pitching analytics.

The Royals value his ability to break down such advanced stats as expected batting average (xBA) and fielding independent pitching (FIP). Both are utilized to help measure a pitcher’s success.

“I think Bove and Sweeney are good at balancing each other out,” right-handed reliever Chris Stratton said. “I think Sweeney has the experience and Bove is the newcomer with the new-school stuff.

Sweeney kind of keeps that old-school mentality that you need at times. But overall (they’re) just two great guys that are trying to get everybody better.”

The Royals also hired Mitch Stetter as their bullpen coach; he plays a key role in helping select members of KC’s relief corps prepare for high-leverage roles.

Rounding out the brain trust are pitching strategists Malcom Culver, Andy Ferguson and Allan de San Miguel. They assist in generating optimal plans and scouting reports for each pitcher.

The group helps Sweeney and Bove in multiple ways. In turn, they’ve aided in the players overall improvement.

Before Wednesday’s game, a 3-0 Royals shutout of the L.A. Angels, KC had a 3.80 team ERA — fourth best in the American League. And all five starting pitchers have ERAs under 4.00.

This season, frontline aces Cole Ragans (a lefty) and Seth Lugo (a righty) were first-time All Stars. Wacha and right-hander Brady Singer have been stellar, too, and new acquisition Michael Lorenzen has bolstered the group even further.

Lorenzen, a right-hander, picked up another victory Wednesday at Kauffman Stadium. Formerly with the Texas Rangers, he has allowed just five earned runs in four starts since joining the Royals.

“Our starters have been unbelievable this year,” Smith said. “They have made the bullpen less taxed. When you’ve only got to roll out there and get nine outs a night between eight guys out there, that’s pretty easy.”

The bullpen also seems to be starting to find its way.

Right-handers Lucas Erceg and Hunter Harvey have carved out trusted later-inning roles. Southpaw Kris Bubic, a former starter, is now a middle-innings option alongside Smith, Stratton and lefty Sam Long.

Every pitcher seems content in his role, and that may have a lot to do with how well both Sweeney and Bove prepare them for action each night.

“They are a good tag-team in different areas,” Long said. “I like going to them for anything — either one of them. They have helped me out a ton with the scouting reports and the mental side.”

A problem-solving solution

The Royals took a chance on several pitchers this offseason. Long, for instance, was a non-roster invitee who has found a home in Kansas City.

Sweeney noticed something special about Long’s reverse splits in getting both right- and left-handers out at the plate. He worked with Long to develop more deception in his repertoire.

He advised Long to pitch farther out to the first-base side of the mound in hopes of creating a better angle for shaping his pitches to the batter.

“I think moving over to the mound a little bit was an easier way to create the angle (when throwing the baseball),” Long said. “It looks like it’s coming in a little bit more horizontally and I’m just understanding what I need to go to when I’m ahead of batters.”

The adjustment worked wonders. Long has a 2.57 ERA and right-handers are hitting just .200 against him this season.

Reliever James McArthur, a 27-year-old right-hander, has his own story of development. After a disappointing major-league debut last season, he regrouped and turned in a solid finish to his rookie campaign.

Hoping to increase his velocity this past offseason, he sought out Sweeney and Bove. Bove spent the winter months walking McArthur through a pitching program. Teaming up with McArthur’s trainer in Florida, he curated a workout plan that included plyometric drills.

The desired results followed.

“Having him in my corner, in that sense, has helped me a lot bridging the gap between the weight room and movement stuff into my pitching delivery,” McArthur said.

Bove had McArthur throw a weighted ball to increase his arm strength. McArthur also threw “velocity bullpens,” sessions in which McArthur would throw harder ... and typically more effectively.

What Bove found was that McArthur was not finishing “front-side” on his delivery. So he corrected that aspect and McArthur saw improvement. His fastball has hovered in the mid-90s this season.

“We slowly saw that average creep up on the back end of the offseason, which was cool,” McArthur said. “Everything kind of came to fruition. I think coming into camp I was 95-96 mph the majority of the time and I felt super consistent.”

The Royals’ roster features still more examples of Sweeney and Bove’s touch. Singer added a sweeper and four-seam fastball; Stratton improved his sinker, and Ragans added a slider last season.

“I’ve learned quite a few things over the last year-plus,” Ragans said. “They kind of help explain the stuff I don’t understand.”

Whether via analytics or a more hands-on approach, Sweeney and Bove have spent countless hours trying to improve KC’s pitching staff. And their combined effort is one of the primary reasons the Royals are 71-56 and eyeing a return to the postseason.

“We want to keep stuff really simple because we all know the game is really hard.” Bove said.

So is the work, so it’s nice when it pays off.

“I just think they are good,” Long said. “They mesh together well and are able to kind of cover all the areas of what a guy is looking for to improve.”

A glimpse into the future

The Royals will continue to evaluate their pitching staff this season and well beyond.

Prospects like Alec Marsh, Anthony Veneziano and Jonathan Bowlan are developing at Triple-A Omaha. Recent first-round draft selection Jac Caglianone may get a chance to be a two-way player at the pro level, and veteran starter Kyle Wright is recovering from a shoulder injury.

Sweeney and Bove are excited to work with the next wave of Royals pitchers. They plan to approach those players, and their development, with open communication and personalized support.

“There is a ton of information out there, but how do we boil it down to a story that resonates with a specific player?” Bove said. “That can be a variety of things.

“Guys come from different experiences, backgrounds and stuff. It’s finding that way to maybe present something that will help them.”