Aaron Bummer

In 2019, Aaron Bummer posted a 216 ERA+ in 67.2 IP. That year, a small group of White Sox fans began congregating on the south side of Chicago. We knew the potential that Aaron Bummer possessed, even despite the admittedly undesirable White Sox defense. If only the White Sox improved their fielding of ground balls by quality signings of defense-oriented middle infielders, one day the sun would shine on the south side's setup man. Aaron Bummer's groundball percentage last year was 58.8% while having a barrel rate 2.9% (!!). In the past two years Aaron has had an incredible unlucky BABIP Against of .362. He deserves a better defense. Since Bummer's trade to the Atlanta Braves, The Church of Aaron Bummer has been looking for a location close to Truist Park to spread the good word of Aaron. The Braves' good (or at least above average) defense should be useful to our cause, of proving that Aaron Bummer is secretely one of the best bullpen arms in the game of baseball. Come join The Church of Aaron Bummer, services held outside Truist Park every sunday home game!

This has to be approaching some kind of record for highest ERA given a high number of appearances, right?

Since July 28 he has pitched 8-2/3 innings, 0 ER, 13 K's, 5 BB's, 2 hits with a 0.81 WHIP. Whatever he has worked out seems to be doing the trick and I am optimistic for the rest of the season.

Funny name man good

I liked all the comments and discussion about Carson Fulmer from my last post, so I decided to do another player discussion post. This one about our fellow reliever, Aaron Bummer.

BACKGROUND:

Bummer is 25 years old. He was selected by the White Sox in the 2014 MLB Draft going in the 19th round and 558th overall. He made his MLB debut on July 27, 2017. He is a left-handed reliever for us.

2018 MLB SEASON (Appeared in 37 Games, 31.2 innings):

4.26 ERA, 2.40 FIP, 2.83 xFIP, 2.80 SIERA, 1.58 WHIP, 99 ERA+

64.5 LOB%, .402 BABIP, 6.3 HR/FB%

24.3 K%, 9.95 K/9, 6.9 BB%, 2.84 BB/9

9.7 sw/str%, 53.5 F-strike%, 28.8 O-swing%, 77.5 Contact%, 44.7 Zone%

61.2 GB%, 16.3 FB%, 22.4 LD%

40.8 Pull%, 31.6 Cent%, 27.6 Oppo%

22.4 Soft%, 45.9 Med%, 31.6 Hard%

PITCHES (from Brooks Baseball and Fangraphs):

Sinker - Bummer’s sinker is one of his primary pitches. It averages around 94 mph (96 mph was his fastest) and has heavy sink action. He has a 68.2 GB%, so he can induce a lot of groundballs with this pitch.

Slider - The slider is the other primary pitch for Bummer. It averages around 84 mph and has exceptional depth according to scouts. I would guess that this is his strikeout pitch as it has a 37.5 K% and a 13.7 sw/str% (his highest of any pitch).

Fourseam Fastball – His fastball averages around 94 mph and has less natural movement than the average fourseam. Bummer’s fastball has a high FB% at 83.3%.

Cutter – This is a new pitch that Bummer started to throw this year. It averages around 89 mph and is another pitch of his with a high GB%. He has a 70.0 GB% with this pitch. His cutter has heavy sink and extreme cut action.

Changeup – He only threw 28 changeups this year, so not much to infer about it. It averages around 88 mph.

SPLITS:

VS L - .245/.298/.302, 26.3 K%, 5.3 BB%, 50.0 GB%, 28.9 LD%, 21.1 FB%

VS R - .338/.391/.425, 23 K%, 8.1 BB%, 68.3 GB%, 18.3 LD%, 13.3 FB%

At home - .237/.266/.316, 29.1 K%, 2.5 BB%, 30.2 Soft%, 50.9 Med%, 18.9 Hard%

At away - .386/.462/.456, 18.5 K%, 12.3 BB%, 13.3 Soft%, 40.0 Med%, 46.7 Hard%

At home vs L - .189/.211/.216, 34.2 K%, 0 BB%, .191 wOBA

MY TAKE ON BUMMER:

Bummer is an interesting reliever because I thought he was a LOOGY, but I learned that he actually faced more right-handed batters in 2018. His splits are very different and inconsistent and is something I expect to level out as he pitches more innings. He has a better slash line, K%, and BB% against lefties, but has better batted ball stats against righties. I also learned that he pitches way better at home in every category. The solution? Only let him pitch at home against lefties where he put up a .189/.211/.216, 34.2 K%, 0 BB%, .191 wOBA in 2018. Just kidding, Bummer has some pretty weird splits, but it will definitely stabilize over time. I thought his splits were interesting though.

Another reason why I was so interested in Bummer was because of his advanced metrics. His ERA is above 4, but his FIP, xFIP, and SIERA are all below 3. I think the main reason why there is such a big difference is the fact that HIS BABIP IS OVER .400!!! We don’t even need to look at any other stats to know that he has been unlucky with that BABIP. Want more proof that he has been underperforming/unlucky? His 64.5 LOB% is pretty low (will hopefully increase next season) and his xwOBA (.305) is 18 points lower than his wOBA (.323).

Other than the fact that I think he’s due to be a better pitcher, there are a lot of qualities that I love about Bummer in general. He has an above average K% and BB%. He has a high GB% and has solid contact stats. I also love how he added a cutter to his arsenal, so he is definitely still developing as a pitcher. Also, I like the way he pitches. IDK if it’s considered sidearm, but it looks different and it looks cool. For me at least.

Keep in mind, he only pitched about 30 innings this season, so there’s not enough information to predict Bummer’s future really, but I did it anyways cause fuck it. I’m not saying Bummer will be our closer or anything, but I think he has some upside to him. He has a pretty good K%, is a groundball pitcher, and has diversity in his pitch arsenal. Let me know what you think in the comments below!