The back end of the rotation

Well, here we are. Through the Royals' first 20 games of the season, they have a record of 7-13. There are a few obvious topics that most fans have had problems with, the offense’s slumping, the runners left on base, the contact plays, the bunting, and of course the back end of the rotation. I want to focus on that last part, “the back end of the rotation”. A team is only as strong as its weakest link and while there have been some great performances from the first three starters, the last few are just as critical to this team’s success.

The First Three

Now 12 percent into the season, the best three starters have been without a doubt Brad Keller, Zack Greinke, and Daniel Lynch. Combined, these three pitchers have put up a 2.93 ERA in 12 starts with 67 ²⁄₃ innings. In that time they have 43 strikeouts and 13 walks for a 3.31 ratio and a 0.99 WHIP.

These three have kept the team in nearly every game they have pitched in and have been a pleasant surprise to all fans. Brad Keller looks like he is back and better than ever and if his small four-game sample isn’t enough to impress you then see below:

Zack Greinke has been as advertised if not better and has been able to pitch to contact without having the runs pile up thus far. Then finally, Daniel Lynch has looked spectacular and has been lowering his walks while upping his strikeouts.

The Problem

If you haven’t been following along much this early on and have heard words of encouragement about this team’s bullpen and are now reading the stats above from 60% of the Royals' starting rotation, you may begin to question how the team is already six games under .500. Well, aside from the offense, the current back end of the rotation manned by Carlos Hernández and Kris Bubic has not shown as much of the promise we hoped for from 2021. These two pitchers’ have combined for a 7.80 ERA in eight starts over 30 innings with 16 strikeouts and 19 walks for a 0.84 ratio and a 1.97 WHIP.

Carlos Hernández was one of the best young pitchers for this team last year with a 3.68 ERA and 1.28 WHIP over 85.2 innings pitched. In 2021, opponents batted .216 on his fastball (thrown 55.7% of the time) and the pitch was averaging 97.2 mph. So far in 2022, Carlos is only throwing his fastball 47.7% of the time at an average of 95.3 mph and opponents are batting .500 against it. He has been throwing his curve more and getting better results than before with that pitch, but he really needs to locate his fastball better in the meantime while its velocity works its way back up.

Kris Bubic was also one of the better young arms for the team in 2021 where he mustered up a 4.43 ERA and 1.38 WHIP across 130 innings pitched. Now, out of the entire MLB, Kris is currently in the 10^th or below percentile in xwOBA, xERA, xBA, xSLG, Barrel%, K%, BB%, Whiff%, and Chase Rate. If you are not familiar with any of these stats or just simply aren’t too fond of any advanced stats, all that really matters is that in 2021 he was not below the 10^th percentile in any of these categories. His biggest difference this year by pitch is also his fastball. Last season opponents slugged only .355 against it and thus far in 2022, they are slugging .808 against it. Through his first four starts, Kris is getting 6.8%, 3.8%, and 8.3% less swings and misses on his fastball, changeup, and curveball respectively compared to 2021.

Both pitchers seem to have much less control than they did last year which is also displayed by both of their increases in walks. While a lot of these numbers are alarming, it would be crazy not to expect some positive regression after what we have seen from both pitchers before. After all, it has only been four starts for each of them. The real wildcard here in the back half of the rotation includes another young arm that has yet to make a start in 2022

Brady Singer

Appearing in only three games of relief so far in 2022, and having just been sent down to Triple-A, it is very easy to forget about Brady Singer. He has a career 4.67 ERA, 4.06 FIP, and 1.422 WHIP across 42 games (39 starts). The original plan starting out the season was for the five-man rotation to consist of Greinke, Keller, Bubic, Hernández, and Lynch in that order. A month into the season, Brady has had a mixed bag of only 5 ²⁄₃ innings of major league work and was just recently sent to Omaha to stretch back out as a starter. The only problem becomes who he replaces.

Out of the six starters mentioned now, three of them are locked in the rotation, and three of them have all shown great potential over their short tenures. So what is the next step? Both Kris Bubic and Carlos Hernández took reps out of the bullpen last season and looked good doing so, but one of the original reasons for having Brady out of the rotation was seemingly his lack of a third pitch. He has a sinker and a slider fully in his repertoire and has shown very minimal flashes of a change up. Of the 103 pitches thrown in his three appearances this year, only 1 was a change up.

The struggles of Hernández and Bubic have apparently put the team right back to the drawing board with Brady Singer. He will likely get a shot in the rotation as well very soon, but has anything improved or changed since the last time he was out there?

The Other Option

In 2021, the Royals tested out something a little different from most teams and ran out a six-man rotation for a portion of the season. A common theme all around this organization has been the depth at certain positions (See the middle infield, first base, catcher, and starting pitchers). So while the team at its current state is very unlikely to make Keller, Greinke, and Lynchs’ starts less frequent this early on, maybe keep an eye on it as we get deep into the 162.