A lot can change in a year and that’s certainly the case for the Royals' starting rotation. A year ago, Brady Singer found himself on the outside, looking in at the rotation at the conclusion of spring training. He started his season in the bullpen before his eventual demotion to Omaha on April 28. The Royals started their 2022 season with a starting five of Zack Greinke, Brad Keller, Kris Bubic, Carlos Hernández, and Daniel Lynch.

A year later, there’s zero question that Singer will be in the rotation. He was fantastic last season, finishing with a 3.23 ERA over 153.1 innings. Meanwhile, those young arms given a spot ahead of him — Bubic, Lynch, and Hernández — struggled heavily. They struggled so much, in fact, that Kansas City decided to bring Greinke back into the fold for his 20th Major League season. In addition, they signed 12-year veteran Jordan Lyles to fill out the rotation.

As it stands now, the Royals’ rotation looks to be nearly ironed out. Greinke looks excellent in Spring Training and will likely start on Opening Day for just the third time in his Royals career. Singer is safe this season, and Lyles has been ramping up all spring to start after signing a two-year, $17 million contract. Of these four, Brad Keller may be the only uncertainty in the rotation, but he’s been wowing the coaching staff in Arizona with his new curveball. He has looked solid in the spring, ranking 26th among all pitchers with 12 strikeouts over 10.1 innings pitched. He’s also walked just three batters.

With the first four slots all but filled at this point, it begs the question: who claims the final place in the Royals rotation to start the 2023 season? It looks to be a three-horse race right now, between some returning arms from 2022.

On the surface, there isn’t much to like about any of the 2022 results for these young pitchers. All three pitched poorly and although results look better so far in Spring Training, the sample size is as small as the list of effective starting pitchers developed by the Royals in the last 20 years. With so much in common, what sets each pitcher apart in their quest to claim the final spot in the Royals’ rotation? Let’s take a look.

Kris Bubic

Kris Bubic is easily the most established of the young pitchers vying for a rotation spot. He’s made 57 career starts and pitched 309.0 major league innings to this point in his career. He’s also been arguably the most successful of the bunch thus far in his career. He was worth 1.3 bWAR in 2021 alone, ranking fifth among all Royals’ pitchers that season, and his career bWAR of 1.4 is the highest of the three. That may be where the positivity ends for Bubic.

Bubic ranked horrifically among pitchers last season in nearly every major category, according to Baseball Savant. He wasn’t just ranked among the bottom half of pitchers — he ranked among the bottom ten percent. Bubic finished 409th in Hard Hit % at 44.9%. His average exit velocity allowed was 90.0 mph, ranking 370th among all pitchers. Not only did opposing hitters hit the ball hard — they did so often.

Bubic ranked 348 out of 358 qualified pitchers with a .304 batting average allowed. It can’t possibly get much worse for the young lefty that led the entire minor league in strikeouts just four seasons ago. So how can he turn things around? For starters, he should throw his slider. The talk in Arizona last spring was the unveiling of a new slider for Bubic. That slider didn’t translate to the regular season. For whatever reason, he just didn’t throw it. Statcast data shows a total of zero sliders thrown last season which isn’t great for a pitch that was supposed to be impactful.

Again this spring, there’s talk of the slider in Surprise. After starting his spring slightly late due to soreness, Bubic pitched his first inning of the preseason on March 6 against the Diamondbacks. He threw just one inning, allowing two hits but no runs. However, he threw three sliders in that inning, one for a strikeout.

The recipe for success with Bubic this season has to include less reliance on his fastball. He threw the pitch more than 50% of the time last season. That’s too much for a pitch that opponents hit .348 off of. Opposing hitters owned a .587 Slugging percentage off the fastball last season. That ranked 209 out of 225 pitchers (min 100 PA). Instead, he will need to mix in more of his secondary pitches and throw the slider with confidence. If he’s able to do so effectively in the remainder of his innings this spring, it’s possible that Bubic claims the final rotation spot.

Carlos Hernández

Hernández had arguably the worst season of the three in 2022, finishing with a horrific 7.39 ERA over 56.0 innings. His SO9 was just 5.6 — the lowest of his career thus far — and his BB9 nearly matched it at 5.0. Even still, I’d give Hernández an edge over Bubic for the final rotation spot at this point in the spring. The spring sample is small, but Hernández has gotten additional innings in for Team Venezuela in this year’s World Baseball Classic. In those innings, he’s been nothing short of fantastic.

His fastball looks to have more movement than we’ve ever seen. In a relief appearance on May 14, he hit triple digits with the 4-seamer three times. The heat we’ve seen before, but what we haven’t seen was the movement. The fastball saw an average horizontal break of 11 inches. That’s up from an average of 8.1 inches in 2022 and just 7.4 inches in 2021. There was also an average vertical break of 10 inches. For reference, Gerrit Cole averaged 10 inches of both horizontal and vertical break on his fastball in 2022.

FanGraphs released a new pitch modeling statistic this year called Stuff+ that aims to put a number to the overall effectiveness of a pitcher’s arsenal. Here’s how they describe the statistic:

“Stuff+ looks only at the physical characteristics of a pitch. Important features include, but are not limited to, release point, velocity, vertical and horizontal movement, and spin rate.”

By this measurement, Hernández ranked as the fifth-best Royals pitcher in 2022 (min. 30 IP). It’s pretty clear that the poor results on the mound aren’t a result of his pitch arsenal. Sure, the movement will help create more deception and keep hitters off balance. The improvements in his fastball will make his “stuff” even better, but the real root of his struggles stems from pitch location.

BaseballSavant.com

The pitch location data above shows us that Hernández struggled to find the zone last year. His fastball — lacking movement — lived all over the heart of the strike zone. Meanwhile, the three secondary offerings lived mostly out of the zone. The end result was opposing hitters waiting on the 4-seamer. They hit .366 off of it with a .581 Slugging percentage. Both of those marks were even worse than Kris Bubic’s fastball.

In order for him to claim the final rotation spot, it’s important for Hernández to show an ability to locate those secondary offerings more this spring. This is a perfect situation that can be aided by Brian Sweeney’s Raid the Zone philosophy. The stuff is there for him, but it’s important for the pitcher to have trust in his ability and trust his pitches to get hitters out. That wasn’t the case in 2022. If Hernández can live in the zone more and let his arsenal work for him, then the sky is the limit. Venezuela plays Team USA this Saturday. That should give the right-hander a chance to showcase his stuff against some premium talent.

Daniel Lynch

Finally, we’ve made our way to Daniel Lynch. He owns a career ERA of 5.32 over 199.2 major league innings — a far cry from the results we all hoped for after he peaked as the number 61 prospect on MLB Pipeline’s Top 100 prospects in 2020. In 2022 he was the fifth-worst among 358 qualified pitchers with a 47.7% Hard Hit%. Much like Bubic and Hernández, Lynch’s fastball was hit often and hit hard. Opponents hit .305 off the pitch with a 52.2% hard-hit rate. That won’t cut it in the major leagues.

At its roots, the major issue with Lynch’s fastball is not too different from what we saw with Hernández and his 4-seamer — a lack of movement.

https://baseballsavant.mlb.com/leaderboard/pitch-movement

There’s Daniel Lynch — smack in the middle with one of the most average fastballs in the major leagues last season. In order for the pitch to be successful, it needs more life. If Lynch could create some movement, similar to what we’ve seen from his teammate in Hernández, it would certainly create more deception and more success on the mound. In 2022, the pitch was average and lived in the heart of the strike zone. With both of those things being true, it’s no wonder the league teed off all year long.

Beyond the fastball, Lynch seemed to face some bad luck in 2022. I wanted to compare his season with that of another pitcher: Taijuan Walker. Walker isn’t entirely similar to Lynch. He throws from the right side, for one. He’s also older, with more innings under his belt. However, his pitch arsenal is fairly similar as is his velocity. Beyond his makeup, he threw a very comparable number of pitches and innings last season to what Lynch tossed for Kansas City.

The results are interesting. Lynch walked more batters per nine but also struck out more. Walker was well below average, finishing the season in the 26th percentile for hard-hit rate. That’s not as poor as Lynch’s mark, but it still ranked in the bottom third of all qualified pitchers. Despite similarities in sample size, hard-hit rate, and SO/BB, there was a drastic difference in BAA and ERA. Walker finished with a .239 BAA, compared to Lynch’s .285. That helped Walker finish the year with a 3.49 ERA — much more respectable than Lynch’s 5.13.

The story for Lynch in 2023 very well may end up being positive regression. His FIP last season was 4.63 and points to him being much better on the mound than a 5.13 ERA may suggest. Beyond that, his xFIP finished at a respectable 4.30. For reference, Zack Greinke’s xFIP in 2022 was 4.54. Luck plays a larger role than can be quantified in the game of baseball and Danny Lynch certainly didn’t have great luck last year. Opponents had a .335 average on balls in play last season. The league average was .290. If Lynch can breathe new life into his fastball and pair that with some regression to the mean this season, it’s certainly possible he takes a leap forward much like we saw Brady Singer accomplish last season.