Another Change of Scenery for New Cub Brad Boxberger

The Cubs added to their bullpen on Thursday, signing veteran journeyman Brad Boxberger to a one-year deal with a mutual option for a total guaranteed value of $2.8 million. The 34-year-old right-hander is coming off an effective stint just up I-94 in Milwaukee, where he served as a reliable middle-innings complement to Devin Williams and Josh Hader for the bulk of two seasons after signing as a minor league free agent in spring training of 2021. In those two campaigns, he made 141 appearances, posting a 3.15 ERA, a 3.61 FIP, 10.56 K/9, and 1.5 WAR. Despite his effectiveness with the Brewers, Milwaukee declined to bring him back on a $3 million team option last month, and instead he’ll join a young Chicago bullpen that could use some help after ranking 28th out of 30 bullpens in 2022 in WAR, 25th in situational wins, and second in blown saves.

Thanks to the circumstances of his contracts, Boxberger will end up with a higher guarantee moving forward than he would have if the Brewers had picked up his extra year. According to president of baseball operations Matt Arnold, Boxberger was exposed to waivers and went unclaimed prior to Milwaukee’s decision, which told him that “the market did not value him at the level of the option value.” After they declined, Boxberger was issued a $750,000 buyout and signed for a guarantee of just $200,000 less than the option value, giving him an effective guarantee of over $3.5 million. The structure of his new deal fits the Cubs’ somewhat recent signature of a one-year deal with an unlikely mutual option, giving him a base salary of $2 million in 2023 with an $800,000 buyout on a $5 million dollar mutual option for 2024.

A 34-year-old reliever isn’t exactly the type of signing that will break the bank, and on the scale of this winter’s relief market, during which relievers have agreed to over a quarter of a billion dollars’ worth of guarantees, the $2.8 million price tag on Boxberger seems like a reasonable pot to gamble that he might be able to reproduce what’s been working well for him the last few years. Like many 34-year-olds, he’s lost some speed off his fastball, down from a 93.5 mph average in 2021 to 92.8 in ’22, and with that has come a decrease in strikeouts. As recently as 2021, Boxberger was a bona fide strikeout guy, but along with the velocity, he lost a lot of his swing-and-miss, going from the 90th percentile in strikeout rate and 85th in whiff rate in 2021 to the 67th and 40th percentiles in those stats, respectively, last season. That’s a scary trajectory for a pitcher at this stage in his career.

That being said, while his strikeout figures went down, Boxberger improved significantly in his ability to limit hard contact. From 2021 to ’22, his hard contact percentage dropped from 34.4% to 28.1%, his average exit velocity from 88.3 to 86.4, and his home runs per nine innings from 1.11 to 0.84. In many ways, his transformation mirrored the shift the whole league experienced: fewer strikeouts and missed bats, but enough poor contact to keep offensive production down. It’s enough to suggest that Boxberger might have benefitted from the changes in the ball that helped pitchers around the league limit lineups to one of the weakest offensive seasons in recent memory. But he improved compared to the league as well, which also suggests that he features the type of arsenal that can survive a tick down in fastball velocity without rendering it useless.

Speaking of, it seems that a chunk of Boxberger’s success with Milwaukee is owed to a renewed comfort level with his changeup, a pitch that garnered praise from his former manager Joe Maddon early in his career before becoming a challenge to harness for a couple of those journeying years. He took a couple of steps forward with the changeup while with the Brewers, improving it from a pitch worth -1.87 runs above average per 100 uses in 2020 to -0.37 in 2021 and then 0.59 in 2022. In a year during which limiting hard contact was a recipe for success, an effective changeup was a great asset; changeups drew the softest contact of any pitch across the league in 2022, with an average exit velocity of 86.0 mph.

Boxberger’s comfort level with his changeup was apparent in his ability to control it. Take a look at the difference between his changeup usage in 2019 and ’22:

Boxberger not only controlled the changeup better, but he also challenged hitters with it more on the lower half of the strike zone. He hasn’t been able to induce many chases since much earlier in his career, qualifying no higher than the sixth percentile since 2015, but if he can trust the changeup to induce weak contact, he can come after hitters with the hope of missing barrels if not missing bats.

His ability to locate his changeup is in part the result of more command over how it moves. Back in 2019, his three-pitch mix was muddled, as he struggled to repeat his offspeed pitches in terms of their movement horizontally and vertically:

By last year, velocity notwithstanding, his arsenal was much crisper, with each of his pitches having a more distinct and precise shape:

As his modest free-agent salary would suggest, Boxberger can’t be expected to have a massive impact on any team at this stage in his career, but the Cubs need help in their bullpen badly, and he was available at a reasonable cost to the club. Coming off two strong seasons, his challenge now is to continue to battle time. If 2022 was any indication (and if MLB leaves the ball be), the 11-year major leaguer may have the tools to remain an effective contributor, and perhaps a valuable veteran leader, in his seventh big league bullpen.