Watching Wade Davis pitch in his prime was an almost religious experience. When Davis entered the game, no matter how dire the situation, you smiled, because you knew that he was going to eradicate the opposition. Davis was an unstoppable monster and a core reason why the 2014 and 2015 Royals teams were so good—if Kansas City got through six innings with the lead, the game was as good as over.
From 2014 through 2016, Davis had a 1.18 ERA over 182.2 innings. He struck out four batters for every walk. He allowed under a single baserunner per inning. Davis made the All-Star team twice, also accruing Cy Young and MVP votes. And, per Baseball-Reference, he was worth 9.1 Wins Above Replacement.
During those same years, Danny Duffy was a definitively above average pitcher. During the playoffs, Duffy was also a part of the bullpen, but Duffy started the majority of his games over 465.2 innings. While certainly good, sporting an ERA of 3.36 between 2014 and 2016, Duffy didn’t make the All-Star team and didn’t receive any Cy Young votes; 24 other pitchers with at least 450 innings pitched had a better ERA.
And yet, over those same years, Duffy accrued 9.4 WAR—more than his world beating reliever teammate.
This discrepancy, between an all-time great reliever and a merely good starting pitcher, illustrates a core fact of baseball: starting pitchers are significantly more valuable than relievers. The best of the best relievers don’t even hit 4 WAR for a full season; 22 starters were worth at least that much last year. Why is this the case? Mostly, it comes down to quantity: your average starter throws three times as many innings as your average reliever. Over one year, that difference is noticeable. Over multiple years, it is significant.
As a result, baseball teams will bend over backwards in order to keep their prospects as starting pitchers. Starters simply offer more value. This is true whether you think WAR is useful or whether you live in the dark ages. But it is also true that good teams need good bullpens. It is also true that good relievers often come from former starters. Davis was one, as were Luke Hochevar and Andrew Miller.
The Royals have a bit of an embarrassment of riches in the pitching prospect front. Just take a look at this list:
- Brad Keller
- Brady Singer
- Kris Bubic
- Daniel Lynch
- Jackson Kowar
- Carlos Hernandez
- Asa Lacy
Keller, Singer, Bubic, and Hernandez have made their big league debuts. Other than Keller, they are all 24 or younger. The rest are poised to make their debuts next year.
Additionally, the Royals have the following pitchers either in the big leagues or minor leagues:
- Danny Duffy
- Jake Junis
- Foster Griffin
- Jonathan Bowlan
- Austin Cox
- Yefri Del Rosario
- Alec Marsh
- Zach Haake
Duffy is still a solid big league pitcher. Junis has been bad this year, but was perfectly average before this year. Griffin made his debut this year before his injury. Bowlan, Cox, and Haake are all a part of the 2018 draft class that have done very well in the minor leagues in their own right. Del Rosario and Marsh are intriguing guys who have suffered from a lack of a minor league season to show their mettle.
Look: There Is No Such Thing as a Pitching Prospect, as they say. They get hurt, they disappoint, they don’t do what you expect. But there are only so many rotation spots, and there are too many young arms coming up through the system than there are spots.
Ultimately, we know that not all of these guys will succeed. Not all will make the big leagues. Perhaps most won’t—such is the life of a baseball prospect. But the Royals have enough minor league talent that they will need to decide which of their current group of starters, in Kansas City and elsewhere, will best succeed as a starter or as a bullpen arm.
Does Kansas City have the guts to move Singer to the bullpen if he doesn’t truly improve against left-handed batters? Will they move Junis to the bullpen, even though he counts as a vet on this team and has had success recently? Which prospects will get moved to the bullpen, and why, and when? Would Mike Matheny make Duffy the closer, a la Ian Kennedy, in order to make room for players with a brighter future?
Again, it might not matter. Prospects have a way of sorting themselves out. But with four young arms already in the rotation this year, and more on the way, Kansas City may have to determine which of its heralded starting pitching prospects could become the next great bullpen arm, even though they would have less value. And they may have to do it sooner rather than later.