The Royals Make a Bad Bullpen Better

Late Wednesday afternoon, word broke that the Royals were “closing in” on a one-year contract with 30-year-old reliever Brad Boxberger. Jon Heyman reported the deal will be for $2.2 million guaranteed, plus $1 million in incentives. Boxberger wasn’t one of our Top 50 Free Agents here at FanGraphs, so we don’t have a crowdsourced contract prediction on record, but his deal strikes me as right around what you’d expect given recent reliever deals (a rejuvenated Óliver Pérez, for example, just signed for $2.5 million, albeit with an option for 2020) and the fact that the Diamondbacks chose to non-tender Boxberger last fall rather than pay the $4.9 million he was expected to get in arbitration.

Boxberger was an All-Star as recently as 2015, when he saved 41 games and posted a 27% strikeout rate for the Rays. But he struggled badly in 2016 and ended the year with a 17% walk rate and an ugly 4.81 ERA. 2017 was a bit of an improvement on both fronts (the walk rate was back down to 9%, and the ERA to 3.38), but Boxberberg’s 2018 campaign in Arizona saw the seesaw dip back yet again, with a 4.39 ERA and 14% free pass rate. The difference between those two bad 2018 numbers, and his two good ones — a 30 percent strikeout rate and 32 saves — is probably what led Arizona to cut ties with their closer last fall. Arbitrators like save totals perhaps more than they should, and with Boxberger’s season having trended in the wrong direction (compare a first-half ERA of 3.06 to a second-half mark of 7.00), Arizona was clearly ready to move on.

How you feel about Boxberger’s ability to return to form in 2019 depends a great deal on whether you believe he can recover some fastball velocity, or offset the loss with an adjustment to his off-speed offerings. With the exception of a slider that he throws fairly infrequently (just 3% of the time in 2018), Boxberger is basically a two-pitch guy: he’s got a four-seam fastball that he throws up and away to lefties and down and away to righties, and a changeup, which he throws down and away from lefties and just plain down to righties. Unfortunately for the reliever, a slight decrease in fastball velocity (from 94 mph just three years ago to 92 mph last year) without an attendant decrease in changeup velocity has left the pitches too easy for batters to distinguish from each other, and last year saw Boxberger generate fewer swings on pitches outside the zone (28%) than ever before. When he was humming in 2015, that figure was 34%.

Still, if Boxberger is able to get some mustard back on his fastball or otherwise distinguish it more meaningfully from his changeup, there’s little reason to think he can’t put up strikeout numbers that more closely resemble last year’s impressive mark while simultaneously reducing his walk rate to a more reasonable level. If he can, it’ll be a boon for a Kansas City bullpen that was, to put it mildly, atrocious last year. Their collective FIP of 4.85 was, by a fair margin, the worst in the game (the runner-up Mets posted a 4.61 FIP; the 24-point gap between the two teams is the same as the difference between the Mets and the seventh-worst Reds). Their 5.04 ERA was second-worst. They struck out a league-low 7.31 batters per nine innings, and walked 4.15 (sixth-worst). Kelvin Herrera was pretty good for a little while there, but then he got traded. Brad Keller was ok, too. The rest of the Kansas City ‘pen was pretty awful. By WAR, only six teams in the last twenty years have been worse:

Worst Bullpens by WAR, 1999-2018
Team Team Relief WAR
2013 Astros -5.2
2016 Reds -3.8
2010 Diamondbacks -3.3
2007 Devil Rays -3.1
2002 Devil Rays -2.6
1999 Royals -2.4
2018 Royals -2.2

In signing Boxberger, the Royals have taken a positive step toward correcting their biggest weakness. According to Baseball-Reference, Kansas City has acquired nine players since November 1, excluding Boxberger. Five are position players. The other four are relievers. Of those four, just one — Jason Adam, signed as a free agent in mid-December — threw any major league relief innings at all in 2018. Another, Michael Ynoa, had some modest success for the White Sox in 2016 and 2017 but was released in March of 2018 and did not pitch in affiliated ball last season. Andrés Machado was last seen posting a 22.09 ERA for the 2017 Royals, and barely counts as an acquisition; he was non-tendered on November 30th and re-signed to a minor-league deal on December 3. Winston Abreu is 41 and last pitched in the majors in 2009, when he threw 3.2 innings for Tampa Bay and 2.1 Cleveland. I wish them all well, but All-Star arms they are not. Boxberger was, and at least could be again.

Even if the Royals had signed Andrew Miller, Adam Ottavino, Jeurys Familia, David Robertson, and Craig Kimbrel this offseason, they likely wouldn’t have a winning team in 2019. As things stand, our depth charts have them besting only the Orioles in total roster WAR. There is, clearly, a lot of room to grow their win total without threatening Cleveland or even the Twins for the AL Central crown. But what we can say at this point is this: the 2018 Royals had one of the very worst bullpens of the last 20 years, and yesterday they went out and did something about it, despite having no real expectation of winning anything at all in 2019. I still think they could stand to bring on a few more relief pitchers, but in this era in which 30 teams seem to be in competition for the 2022 World Series but only ten or so are in competition for the one this October, there’s at least some consolation in what they did yesterday.

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Rian Watt is a contributor to FanGraphs based in Seattle. His work has appeared at Vice, Baseball Prospectus, The Athletic, FiveThirtyEight, and some other places too. By day, he works with communities around the world to end homelessness.

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What does this mean for Peralta? Will Box eat up *all the saves* sooner or later?


On a team where the word ‘closer’ is synonymous to ‘whoever is not currently imploding’, Boxberger has a good chance to get some or all the saves as long as he recovers some of his old form.