Chicago White Sox: A Real Bummer of a Deal

The Chicago White Sox have inked reliever Aaron Bummer to a five year deal worth $16M. The White Sox get cost certainty over a surprisingly good reliever.

Spring training means its extension season and the Chicago White Sox have started by inking LHP reliever Aaron Bummer to a rather unprecedented five year deal. The deal is a $16M guaranteed with two team options that could increase the value to $29.5M.

This is a rather unprecedented extension but a smart deal for Bummer. He is 26 years old and wouldn’t do well in arbitration since he is a reliever who doesn’t rack of a ton of saves. Bummer has one career save but is a good reliever who you should get to know immediately.

After making a less than stellar 22 inning debut where he recorded a negative WAR in 2017, Bummer was good in 2018 and then broke out in 2019 in a big way. Bummer threw 67.2 innings with a 23% strikeout rate and a 1.3 fWAR total that was top 25 among all relievers in baseball.

The most valuable part of Bummer’s profile is his incredible groundball rate. Among all qualified relievers, Bummer ran the second highest GB rate in baseball at a worm burning 72% behind only Zack Britton. For those who prefer visuals, consider Bummer’s power sinker and cutter below.

A power sinker that hits 97 and a delivery that has a little bit of funk, Bummer is quite the reliever. That sinker is a primary pitch and its a very low (12th percentile) spin offering that was made to generate grounders.

For expected statistics, Bummer was one of the best pitchers in the league for expected batting average, slugging, and xwOBA so this isn’t a flash in the pan scenario. Bummer is a legitimate relief asset.

Bummer was never going to rack up big numbers in arbitration since he is a reliever with only 1 career save. The Chicago White Sox get cost certainty over a groundball machine who will feature heavily on all their competitive teams over the next decade. Meanwhile, Bummer gets more money than he would have otherwise since he wouldn’t be a free agent until he was in his 30s.

With the volatility of relief pitchers, Aaron Bummer was smart to take the guarantee now. Both did well here and now, we are all aware of an elite relief pitcher we didn’t know about before.