Grading the White Sox: Aaron Bummer

At midseason, the SSS staff graded the 46-46 White Sox, from the head of the class Dylan Cease down to Dallas Keuchel. We invented a WARsss metric that could very well be just a cute way to trot out our special site grades — but really for all you know could be the product of years of research in a stats lab.

Our expanded report card will take us through everyone who saw time in uniform for the White Sox, plus some front-office types. Most of our writers will take on a couple of players, with final grades and short writeups, running through the end of November. Enjoy!

Aaron Bummer
Left-Handed Relief Pitcher
Midseason: 1.9 WARsss
Final: 1.8 WARsss

Aaron Bummer is another interesting case of injuries and slight underperformance, which seems like a summary of the White Sox 2022 season. If the saying “your best ability is your availability” is true, Bummer should get docked for missing the better part of three months with a lat strain. Is it somewhat unfair to dock someone for injury? Possibly, but with the level of injuries the White Sox have sustained, injuries definitely need to be taken into account in our evaluation of these players.

I am a huge fan of Bummer. Because I like to bring a playing background along with analytics, I’ll break his season down both ways.

Eye Test

At his best, Bummer is a ground ball machine — someone who limits home runs and extra base hits to the point where it typically takes three good swings to score a run. In two- or three-run games, he is the perfect guy to bring in because you don’t have to worry about a crooked number going up in one swing.

However, the one big question mark with a healthy Bummer has always been command. Free passes can easily turn that three good swings formula into two or even one swing to score a run. I’d love to see Bummer challenge hitters more aggressively from the first pitch of his outings. It is way too common to see Bummer come into a game and fall behind or even walk a hitter or two before settling in. With Bummer’s nasty sinker/slider combination, set the target at the bottom of the zone and don’t get too cute nibbling on corners.

Analytics Dive

I look at Bummer’s 48% zone rate in 2022 and see him right in line with his 49% average from 2019-21, which was a bit surprising to me. However, like I alluded to in the eye test portion, Bummer’s 56% first pitch-strike percentage from 2019-21 dropped to 48% in 2022. Hitters also stopped swinging as often on all pitches, dropping from a 45% swing rate down to 37%. A first pitch ball automatically gives the hitter the advantage, putting him in a selective mindset rather than getting ahead and getting the hitter on his heels from the jump, making them more prone to chasing. This leads to deeper counts and more potential for walks.

In addition, when Bummer was in the zone this year, he was up in the zone more often than usual.

Baseball Savant

Baseball Savant

This contributed to a major decrease in his ground ball rate, going from an astronomically-high 66% in 2021 to 52% in 2022, with this 14% decrease leading to increases in both his line-drive and fly-ball rates.

Despite all this, Bummer still had pretty solid results when healthy, pitching to a 2.36 ERA and 3.19 FIP and not allowing an earned run in 27 out of 32 appearances. If he can start getting ahead more often and get back to locating that sinker at the bottom of the zone, he should be in line to be a major weapon again in 2023.

2022 White Sox Grades

Aaron Bummer, LHRP, 1.8
AJ Pollock, OF, 1.3
Matt Foster, RHRP, 1.2
Yoán Moncada, 3B, 0.92
Lenyn Sosa, SS, 0.85
José Ruiz, RHRP, 0.83
Mark Payton, OF, 0.6
Carlos Pérez, C, 0.399
Lucas Giolito, RHSP, 0.392
Adam Engel, OF, 0.237
Vince Velasquez, RHP, -0.4
Reese McGuire, C, -1.1
Kyle Crick, RHRP, -1.65
Joe Kelly, RHRP, -1.75
Daryl Boston, 1B Coach, -2.0
Anderson Severino, LHRP, -2.2
Jerry Reinsdorf, OWN, -2.321
Jake Diekman, LHRP, -2.366
Rick Hahn, GM, -2.401
Bennett Sousa, LHRP, -2.425
Frank Menechino, BAT COACH, -2.469
Yasmani Grandal, C/DH, -2.549
Leury García, UTIL, -2.7
Adam Haseley, OF, -3.146
Joe McEwing, 3B Coach, -3.167
Ryan Burr, RHRP, -3.4
Tony La Russa, MGR, -3.5
Dallas Keuchel, LHSP, -3.9