Thursday Tidbits: Regal Relievers

It’s no secret that the Arizona bullpen quickly went downhill with the dual loss of AJ Puk and Justin Martinez earlier this year. Of course, it’s also an open secret that Mike Hazen and his staff have struggled to put together strong bullpens in the past. The problem is bad enough that our own Jim McLennan detailed exactly how badly Hazen has been at acquiring, drafting and developing, and signing pitching talent in his tenure. It’s been a particularly stark problem in the bullpen to be sure, but his track record with starting pitchers has been spotty at best (*cough* *cough* Madison Bumgarner). And while the current mess of a bullpen stems more from injuries than anything else, it’s still a worrying trend that Hazen and his team need to address somehow if the team will try to pivot back into postseason contention next season. But with the Baseball Writers Association announcing earlier this week that they will be awarding an NL and AL Reliever of the Year Award starting next season, I thought it might be worthwhile to look back through the franchise history to see some of the best relievers we’ve seen pass through Chase Field.

Archie Bradley – 2017

Bradley had arguably the best season out of the bullpen in franchise history for the 2017 club – one of the last times the D-Backs had an above-average bullpen with a collective 3.78 ERA which was fifth in the majors that season. Ironically, Bradley wasn’t even the closer for that iteration of the D-Backs. That role actually went to Fernando Rodney instead who collected 39 saves on the year despite his 4.23 ERA and 1.19 WHIP for the season. Even still, Bradley managed to accumulate 3.5 bWAR with his incredible performance – including a 1.73 ERA and a miniscule 1.04 WHIP, good enough for a 273 ERA+ and even netted the Oklahoman downballot MVP votes. The bearded wonder essentially worked off a two-pitch mix with his four-seam fastball getting 75% usage alongside a devastating curveball for another 21%. His fastball averaged a touch over 96 while the curve averaged out at 82. That kind of movement and speed differential was nearly impossible for batters to detect as the latter featured an impressive 26% whiff rate on the year. He would have been a prime candidate for NL Reliever of the Year that season were it not for Corey Knebel out of Milwaukee who put together an equally impressive season that included a 1.78 ERA and 1.15 WHIP. Sadly, it was a career year for the righty as he never even came close to producing a similar portfolio across an entire season – a result that is far too common for relievers and the continued variance they can experience year-over-year.

Byung-Hyun Kim – 2002

Much like Bradley, Kim’s breakout season in 2001 was somewhat out of nowhere. An international signee back in 1999, Kim forced himself into the bullpen picture that same season and the following season with moderate success. But after that breakout, Kim was actually even better in 2002. He lowered his ERA from a respectable 2.94 to an absurd 2.04 while his WHIP stayed remarkably consistent across his first three seasons. Of course, that was a team coming off a World Series win and the team as a whole got even better in the offseason. Unfortunately, we don’t have any statcast data from this era, but he still managed to distinguish himself on a pitching staff that also included one Hall of Famer in Randy Johnson and another fringe candidate in Curt Schilling.

I don’t mean to suggest that the team will have to find someone of this caliber in the offseason. These kinds of relievers are understandably rare, but that can’t stop Hazen and his staff from attempting to overhaul their approach to the bullpen and the starting rotation. Whether that includes yet another coaching change for pitchers is still up for debate, but there needs to be some serious self-reflection on why there appears to be a pattern of struggles for pitchers upon entering the organization.