Madison Bumgarner’s Fastball is (Still) Broken

If something about Madison Bumgarner’s first eight starts of 2018 have seemed odd to you, it’s because they have been. No matter the fielding independent pitching statistic to which you subscribe — FIP, xFIP, SIERA (although, frankly, it should be SIERA) — Bumgarner’s 2018 has not inspired confidence. Despite a dazzling (and quintessentially Bumgarnerian) 2.90 ERA, his baserunner suppression skills (i.e. strikeouts and walks) have lagged this year, and the various FIPs all portend severe bumps in the road. Granted, Bumgarner has outperformed his FIPs the last three years and throughout his career. I’m here to argue not that we should dismiss our concerns because of this but, instead, that such overperformance has insulated us from what should be potentially serious concerns about MadBum’s long-term health and success.

The problems with Bumgarner’s 2018 season — or at least the peripherals that underpin his 2018 season — thus far stem back not to his broken finger but, rather, something both farther back and much more dire. You may or may not recall Bumgarner fell off a dirt bike last year and injured his throwing shoulder. He returned from that injury almost exactly a year ago and promptly underwhelmed us. Sure, he posted a 3.43 ERA through September and has a 3.23 ERA in the calendar year since his return. It’s not vintage Bumgarner, but it’s not awful. But the peripherals, oh, the peripherals: his strikeout rate (K%) has caved dramatically, falling more than 6 percentage points (27.1% from April 2015 through April 2017; 20.9% from July 2017 onward).

It’s his fastball. Bumgarner’s fastball, once elite (relative to other four-seamers), is broken, and it has been broken for a year.

Being a fantasy analyst has its hits and misses. Sometimes you have to pat yourself on the back for a good call. The caption I wrote for Bumgarner’s player page this year (which, of course, preceded the 2018 season) included the following prescient snippet:

Part of MadBum’s success stems from his effective fastball: from 2013-16, his ranked 7th of 263 in SwStr%. Where the average four-seamer induced swinging strikes 7.7% of the time, his notched a lofty 11.9%. That rate fell to 7.3% in 2017. It trended positively through the end of the season, creeping up to 9.1% in September, but never cracked double digits in any calendar month. Worse: it allowed a .340-plus ISO in August and September, something he hadn’t done in a single month since 2010 and, in consecutive months, ever.

In other words, Bumgarner’s fastball was incredibly vulnerable last year, not only inducing fewer whiffs but also allowing extra-base hits at a rate unprecedented in his career. There were red flags way before he suffered a broken finger; the additional injury has compounded the ill effects. In other other words, I think it’s unwise to expect him to simply shake off the rust.

Bumgarner’s fastball hasn’t been quite as vulnerable this year, allowing a .206 isolated power (ISO), far better than in 2017. That seems to me the rust he shook off, if there were any rust to shake. But the fastball’s low whiff rate leads to more balls in play, which leads to a higher batting average that, coupled with the .206 ISO, produces a career-worst .485 slugging percentage (SLG) allowed. Contextualizing for the current hitting environment, it’d be the most damaging production against his fastball (130 wRC+) in any season after 2010. FanGraphs’ plate discipline splits show that hitters are making contact on in-zone fastballs (Z-Contact%) more than 95% of the time. That’s really bad. Coupled with significantly fewer chased pitches (O-Swing%), it’s apparent the fastball no longer has any deceptive qualities to it. This is his primary pitch we’re talking about, a pitch that has fallen dramatically from grace, from being legitimately plus to legitimately minus during what might be expected to be his peak years. (As to other culprits, I’m not sure; I didn’t see evidence in his pitch locations or movement vectors, but it doesn’t mean those may not also be factors.)

The silver lining: maybe it’s a coincidence, but it seems to me Bumgarner is attuned to the fact his fastball has been failing him. Having thrown the pitch 48% of the time in 2016, he threw it only 41% of the time in the latter half of 2017 and has scaled it back even further this year (38%). He has mixed in a few more curves and change-ups in lieu of the four-seamer, both of which are solid-not-spectacular but at least definitively better than his fastball both by whiffs and ISO allowed. I will typically praise any move toward more breaking and off-speed stuff; for Bumgarner, it fits the mold and seems like the appropriate adjustment. But it’d be nice if Bumgarner had the option to reach back with his fastball. His average fastball velocity seems mostly unchanged, hovering consistently between 91 and 92 mph even before his dirt bike accident, but his maximum velocity (92.8 mph) is at least a full tick lower than its previous low (93.8 mph, in 2016). It’s speculation, but I imagine it is one of the many factors at play here.

I think the Bumgarner we see from here onward will be pretty different from the one to whom we’re accustomed. He can try to get by with diminished fastball velocity and effectiveness, but I’m haunted by memories (and the continual nightmare unfolding in real time) of Felix Hernandez’s diminished velocity and his monumentally failed attempt at reclaiming his former glory. Once the wheels fell of the cart, it stopped moving. The King, like Bumgarner, had the requisite secondary stuff to get by, but once the fastball broke, it was all over. Bumgarner differs from the King in that Bumgarner has no truly weak link in his arsenal (unlike Hernandez, whose sinker was, and is still, very bad, and he continues to feature it as his primary offering). I hope this prevents Bumgarner from descending to the depressing depths at which we now find our deposed King. I hope. But my concerns persist.

Look, I’m not going to tell you to sell Bumgarner (although if you do, now is as good a time as any). It’s possible that, at 28, with a few more months of rehabilitation, his shoulder (and, subsequently, his fastball) heals. He could return to form, at least as defined by his underlying skills, and continue to build an airtight case for the Hall of Fame. But I have also seen shoulder injuries completely debilitate once-excellent pitchers. Honestly, at this point, I fear significant shoulder injuries more than I do Tommy John surgery in terms of a pitcher’s career-long prognosis. And I have seen pitchers outperform their peripherals one last time, as if to stave off the inevitable (as King Felix did in 2015).

Of course, this could all be much ado about nothing. But there are enough red flags here to make me anxious.