After the acquisitions of free-agent starting pitchers Michael Wacha and Seth Lugo, the Royals rotation for 2024 looks pretty set in terms of the No. 1 to No. 4 spots. In addition to Wacha and Lugo, the Royals will have Cole Ragans, the Royals’ 2023 Pitcher of the Year, and Brady Singer, the Royals’ 2022 Pitcher of the Year.
That just leaves the No. 5 spot open for this upcoming season.
Right now, the favorite appears to be Jordan Lyles, whom the Royals signed last offseason to a two-year deal. That said, even though the Royals are paying Lyles $8.5 million this season to “eat innings”, he should have some competition this spring, barring a trade.
Daniel Lynch has long been projected to be an option for the Royals rotation ever since he was drafted in the first round of the 2018 MLB Draft (along with Brady Singer and Kris Bubic). Unfortunately, he has struggled to stay healthy and effective at the Major League level since debuting in 2021, though he showed some signs of being healthy again this fall in a couple of “rehab” starts in the Arizona Fall League.
In addition to Lynch, Alec Marsh, and Angel Zerpa could also figure into the last spot in the Royals rotation.
Even though they fared better in relief roles in 2023 at the Major League level, they could get some seasoning in Spring Training and perhaps in Omaha to begin the season and eventually join the Royals rotation, especially if Lyles or Lynch can’t produce on the mound.
So who should Matt Quatraro go to for the fifth spot in the Royals rotation?
Let’s look at the four starting pitcher candidates and analyze them by their pitch quality, as rated by Pitcher List’s PLV metric. A deeper dive and explanation of Kyle Bland’s PLV metric can be found in this post, but here’s a brief definition of what PLV encompasses.
PLV – Pitcher Level Value – is a pitch quantifier, not unlike Eno Sarris’ Pitching+ and Cameron Grove’s Pitching Bot. In incredibly simple terms, we look at many granular variables of a pitch (release point, count, pitcher/batter handedness, velocity, movement, location, etc.), shove it into a machine-learning prediction model, and based on what we’ve seen across 2020-2022, we can give an overall 0-10 score to say “this was a good pitch or a bad pitch.”
“What Is PLV? – An Introduction To Pitch Level Value And Its Applications” by Nick Pollack; Pitcher List
Thus, PLV gives a glimpse of the pitch quality and outlook of a pitcher’s arsenal. That can be good for not just analyzing a pitcher’s past performance, but projecting future outcomes as well.
Let’s analyze then what all four pitchers offer in the final spot in the Royals rotation, based on their PLV metrics.
Jordan Lyles
2023 Stats: 31 starts; 177.2 IP; 16% K%; 6% BB%; 33.5% GB%; 6.28 ERA; 5.62 FIP; 0.2 fWAR.
Lyles’ 6.28 ERA is comically bad and he wasn’t helped by a HR/FB rate of 14.1% last year. On a positive note, there may be some hope that 2024 may not be as bad for Lyles.
First off, his FIP was 0.66 points lower than his ERA, demonstrating that he wasn’t nearly as bad as his over-six ERA indicated (though still plenty bad). Furthermore, Lyles limited the free passes in 2023, as his 6% walk rate was lower than Lynch and Marsh (though not as low as Zerpa’s 4.4%).
With some batted-ball regression and less pressure in the rotation (he was a No. 2-3 starter last year), it’s possible that we could see Lyles produce a line in 2024 perhaps close to his 2022 one in Baltimore (4.42 ERA; 1.4 fWAR).
In terms of his PLV numbers, Lyles’ profile is split.
He sports three below-average pitches in his repertoire, based on PLV. That includes his curve (4.69), sinker (4.46), and changeup (4.56). On the other hand, his four-seamer (5.01), slider/sweeper (5.51), and cutter (5.52) were not just above-average, but pretty good offerings based on PLV metrics.
Here’s a look at how those particular three pitches played off of each last season.
The sweeper, his second-best pitch based on PLV, worked particularly well against righties, forcing them to chase out of the zone (as demonstrated in the above pitch to Seattle’s Ty France). The cutter, his best pitch based on PLV, was utilized primarily against lefties, as shown in the clip against Boston’s Reese McGuire.
The fastball was an intriguing pitch as Lyles posted a positive PLV on the pitch despite it featuring slower velocity (91.4 MPH) compared to a season ago (91.9 MPH). When Lyles located the four-seamer up in the zone, he generated a lot of whiffs, which can be seen in his four-seam whiff heatmap from last season via Savant.
The critical area of focus for Lyles in 2024 needs to be limiting mistakes in the zone, especially with those pitches that are of low-quality PLV-wise (curve, sinker, change).
If Lyles can do that, and perhaps utilize his cutter more (and maybe the changeup less, as it was another primary pitch against lefties), then it could be possible that Lyles could hold his own at the end of the Royals rotation and perhaps generate some trade value by the August Trade Deadline.
Daniel Lynch
2023 Stats: 9 starts; 52.1 IP; 15.2% K%; 7.2% BB%; 38.8% GB%; 4.64 ERA; 5.17 FIP; 0.3 fWAR.
Lynch’s overall PLV is just one point lower than Lyles though his pitch arsenal PLV profile fares very differently.
Like Lyles, Lynch sports three above-average offerings based on PLV. This includes his four-seamer (4.91), slider (5.15), and changeup (5.01). His curve was below average, but only slightly at 4.97. His only egregiously bad pitch PLV-wise was his sinker, but he only threw that 3% of the time last season.
The four-seamer will be a key pitch for Lynch going forward in 2024. It was above average, but still not a great pitch by any means, especially at 92.6 MPH, which is 1.4 MPH slower than in 2022. The clip compilation below demonstrates his four-seam velocity difference from 2022 (against the Twins) to 2023 (against the Dodgers).
On the other hand, the slider and changeup, which both fared positively on a PLV end could be a great pairing for Lynch going forward. They played well off together when thrown in similar areas of the zone last season, as demonstrated in this clip compilation below.
Both pitches start out the same, but Lynch’s slider breaks sharper horizontally while his changeup has more vertical drop. Therefore, they are both effective weapons when utilized together, especially against hitters who are sitting on a pitch low in the zone.
If Lynch can get the zip back on his four-seamer, he could see the pitch quality increase in 2024. That could help boost his overall numbers and solidify the 5th spot in the rotation both in the short and long term.
In terms of upside, Lynch is a much better option than Lyles, despite carrying more injury risk and unpredictability.
Alec Marsh
2023 Stats: 8 starts (17 games); 74.1 IP; 24.9% K%; 11.4% BB%; 34.6% GB%; 5.69 ERA; 5.70 FIP; -0.5 fWAR.
Marsh has the best strikeout ability of the group, as he sported a 24.9% K rate in his rookie season.
On the other hand, he also possessed the highest walk rate at 11.4%, and his 4.72 PLV was also the worst overall mark of the four pitchers profiled in this post.
The four-seamer (4.49) and changeup (4.56) were both bad pitches overall for Marsh last year on a PLV end. The curve was slightly below average at 4.87, and the slider appeared slightly below average too with a 5.00 mark.
However, the slider PLV is more complicated and merits some context. PLV classifies sweepers as sliders according to their model. Thus, slider PLV can be wonky for pitchers who sport both breaking offerings.
Take a look at Marsh’s pitch usage by month via Savant and notice how Marsh’s slider usage dropped off once Marsh started utilizing a sweeper.
After introducing the sweeper in August, Marsh’s slider usage dropped to under 5% that month and was barely utilized at all in September. The sweeper appeared to be a more effective pitch as well as it sported a 45% whiff rate, which was 8.5% better than the whiff rate of the slider.
Here’s a clip comparison of his slider, utilized in a July start against the Rays at Kauffman, and his sweeper, which produced a whiff against the A’s in Oakland in August.
Honestly, the movement and break of the sweeper are a lot more effective and give some room for error when Marsh doesn’t locate it properly. The slider is a harder offering with less break and while he gets Tampa’s Jonathan Aranda to whiff in that clip, it would also get batted around when it was left up in the zone (.533 SLG on the slider last year).
Marsh is probably better suited for long relief work in 2024, and he thrived in a “bulk-innings” role following an opener down the stretch in 2023.
That said, if he can clean up the pitch quality on his four-seamer and make his sweeper an effective primary breaking pitch, then it isn’t out of the question to think that Marsh could join the Royals rotation again at some point.
Angel Zerpa
2023 Stats: 3 starts (15 games); 42.2 IP; 19.8% K%; 4.4% BB%; 50.8% GB%; 4.85 ERA; 4.54 FIP; 0.1 fWAR.
Zerpa probably is destined for a relief role in 2024, much like Marsh. However, he’s only 24-year-old and he is coming off major surgery in 2022 so there could be some starter upside with Zerpa, should the Royals want to go that route developmentally.
Of the four pitchers analyzed in this post, Zerpa was the best at inducing ground balls, as he produced a GB% over 50% last year. He also still struck out a decent number of hitters in 2023, as evidenced by his 19.8% K rate.
Thus, Zerpa’s combination of solid batted-ball and control profiles makes him an intriguing dark horse for a Royals rotation spot in 2024.
Unfortunately, Zerpa’s overall PLV of 4.84 is pretty underwhelming (only Marsh was worse) and his four-seamer rates poorly on a PLV end at 4.54. That’s the 25th percentile for context. Conversely, the pitch did sport a K rate of 25.9% and a hard-hit rate of 31.6%, so it’s hard to tell what kind of pitch the four-seamer truly is.
Does the pitch simply sport bad spin and movement but is located with such precision that it’s able to overcome those poor PLV metrics long-term? Or did Zerpa get pretty lucky with the pitch and should opt to use his sinker more, which sported an above-average PLV of 5.10?
It seems like Zerpa opts to utilize the four-seamer up and the sinker low and arm side, which pairs better with his changeup.
Here’s a look at how the two pitches both looked last year in Zerpa’s outings in September against the Yankees and White Sox, respectively.
I think Zerpa’s pitch mix works well in low-leverage relief work. However, in longer outings as a starting pitcher? It’s harder to imagine Zerpa finding consistent success in that role unless he can utilize a better breaking pitch (his slider rates as average on a PLV end at 5.15).
Zerpa seems to be on the outside of the rotation bubble here heading into Spring Training in Surprise.
Then again, if Brian Sweeney and Zach Bove can help work their magic with Zerpa on a breaking pitch and improve the quality of his four-seamer, then Zerpa could be a sleeper for 2024 because he controls the strike zone so well (15.4% K-BB% in 2023).
Photo Credit: Ed Zurga/Getty Images
Mr. O’B, I am SO grateful to you for all the analysis youprovide. It is of tremendous help for me inunderstanding the game I love on a deeper level. I am so hoping Wacha and Lugo can succeed andalleviate the team’s dismal history with free agentpitching. Any chance Kris Bubich will be back by mid-summer? It seemed to me he had figured a few things outbefore his unfortunate injury.
You’re welcome! Thank you for always reading and commenting! I appreciate your engagement on here!
I thought about including Bubic but I was hesitant to do so until I got a better sense of his timetable for return. I think he could compete for a job after the trade deadline, especially if Lyles is traded away/DFA’d (don’t think Lyles makes it through the year). I like Bubic’s upside way more than Lynch, Marsh, and Zerpa, but coming back from TJ can always be a tough thing. He may be more of a player for the rotation in ’25.