Brewers: Taking a Statistical Deep-Dive into Bryse Wilson's Career-Altering 2023 Season

What did Bryse Wilson change going into 2023?

After Wilson arrived in Milwaukee, the Brewers and Wilson combined to make two big-time adjustments: mechanical tweaks to his delivery and pitch usage.

Mechanically, tweaks have been made to each individual pitch in his arsenal by release point, but his extension has stayed relatively similar (6.5 ft in 2022 to 6.6 ft in 2023). These changes have been made to affect the break and spin on his pitches and for some, have even affected velocity.

Wilson's cutter has seen the most change from a mechanical perspective, as his vertical release point has shifted from 5.21 feet to 5.62 feet, while his horizontal release point went from -2.51 feet to -2.99 feet. This small mechanical tweak allowed his cutter to gain 3 extra MPH, while gaining an extra inch of arm-side movement and reduced downward movement by over 5 inches. The cutter also gained an average of 80 RPMs of spin. This change effectively gave his cutter a tighter, slider-like movement compared to his more downward-breaking cutter of 2022.

Along with the cutter, Wilson's four-seamer also gained an extra 77 RPMs on average after shifting his release point. His sinker gained almost 90 RPMs on average while gaining about two inches of vertical movement and losing just under two inches of horizontal movement, making it easier to throw for a strike. Finally, his curveball gained over 190 RPMs and 2 inches of vertical movement, while also gaining 2 MPH in velocity.

All of these factors work together to give Wilson a much more complementary pitch mix, with each individual pitch better playing off of each other. After necessary mechanical tweaks were addressed, the usage of these pitches also needed to be changed heavily.

Coming into the 2023 season, Wilson was seen as mostly a sinker-baller pitcher who relied on a high usage of his fastball to force contact on the ground, along with using five other offspeed or breaking pitches. Wilson's sinker and four-seamer combined to be used 56.5% of the time, his curveball was used at 13.6%, slider at 11.1%, his changeup at 9.5%, split-finger at 5.4%, and finally, his cutter was used at 3.9%.

In 2022, Bryse Wilson only had two pitches with a positive run value (effectively, how good a pitch is at limiting runs). His sinker and cutter posted run values of 2 and 1, respectively. All five of his other pitches were below average or average, with his four-seamer and changeup both giving -10 run value, his slider and curveball coming in at -6 and -3, and his splitter at exactly zero run value. These factors combined to give Bryse Wilson the worst pitcher run value in all of baseball last season, at -27.

The Brewers also went to work on finding the best pitch mix for Wilson to carry into 2023. This pitch mix has seen a steep decline in diversity, but a large increase in productivity. His cutter and sinker are both used just above 34%, while his four-seam fastball has been used at 16.1%, and his curveball at 14.1%. His changeup and split-finger have been thrown 8 total times the entire season, and his slider has been cut entirely.

The run value of his pitches improved heavily in 2023, with every pitch but his sinker taking a step forward. The cutter and four-seam fastball both shot up in run value, with the cutter producing a run value of 8 and the four-seam fastball going from a -10 run value last season to a +5 in 2023. His curveball went from below average to exactly average at zero, and his sinker did take a dip, moving from a +2 run value to -1.

The success of Bryse Wilson's cutter has been a big reason for his breakout. The Brewers saw Wilson's cutter put up season-high numbers in K%, BAA, wOBA, Whiff %, and hard-hit rate in 2022 and wanted to see it used more. Along with the uptick in usage, it has become a much more successful pitch during the 2023 season compared to when he started throwing it in 2022.

For a better look at the difference Wilson has made with his cutter this season, I'll start with a video of one of his cutters from 2022. This was a cutter thrown to Yadier Molina in April of 2022. Notice the break of his pitch, and how it looks more like a changeup than a cutter. According to Baseball Savant, this pitch came in at 85.3 MPH, spun at a rate of 2102 RPMs, and broke 33 inches vertically while breaking 1 inch horizontally.

In 2023, Wilson and the Brewers went to the drawing board and reimagined his cutter. This strike thrown to old friend Esteury Ruiz shows exactly what has changed in this pitch during this season. This pitch came in 4 miles an hour faster at 89.4, spun at 2322 RPMs, had only 26 inches of vertical break, but broke horizontally at 6 inches (three inches more than league average). For example, there are only four pitchers in baseball who have an average horizontal break on their cutter of 6 inches.

How has Bryse Wilson impacted the Brewers in 2023?

Bryse Wilson has stepped into his role in Milwaukee's bullpen perfectly in 2023 and has given the Brewers immense value for a pre-arbitration player. He has fit the bill as a great multi-inning reliever who has stepped into a middle relief role at times, provided consistency, and has saved the bullpen multiple times during the season.

In 50 appearances out of the bullpen this season for Milwaukee (72 IP), Wilson has pitched to the tune of a 2.59 ERA and a 166 ERA+. He has a 58/20 K/BB ratio during this season, has picked up three saves, and has held opposing hitters to a .217 batting average against. This body of work has combined to give Wilson a 1.4 bWAR on the season, putting him behind only Devin Williams, Hoby Milner, and Joel Payamps for the most by a Brewers reliever this season.

As the multi-inning reliever for Milwaukee, Wilson has made 20 appearances of over one inning during this season, totaling 48.2 innings in those appearances. He has given up only 11 earned runs in those appearances, tallying a 2.05 ERA. Those multi-inning appearances include three scoreless innings against Atlanta on July 21st, four scoreless against San Diego on August 27th, and two 3-inning saves in April.

Where he has been shockingly good this season is as a one-inning reliever. In 24.1 IP in 30 appearances where he threw one inning or less, Wilson has posted a 3.73 ERA. While this number is much higher than the number as a multi-inning reliever, it is important to add context. Four of Wilson's 10 earned runs allowed in this role came in one appearance on July 28, which is the difference between a 2.24 ERA in these situations and the 3.73 he currently owns. 83.3% of Wilson's appearances in this role have been scoreless, and he hasn't given up an earned run in this role since that July 28th game.

While he hasn't been put in this spot very often throughout the season, Bryse Wilson has also been excellent in medium and high-leverage situations out of the bullpen. In 58 medium-leverage plate appearances, Wilson is holding opponents to a .189 BAA with 12 strikeouts and only 5 runs allowed. In 33 high-leverage plate appearances, Wilson is holding hitters to a .185 BAA, only allowing five hits. In these high-leverage situations, Wilson has been 142% better than the average pitcher in these situations, holding batters to a 58 sOPS, which is OPS+ for a given split relative to the league average.

Wilson has had a season that has seen his percentile rankings rise at every single statistic listed by Baseball Savant. He has done a better job at limiting hard contact, raised his K% by over four points, and kept his command in check. His hard-hit rate, average exit velocity against, and barrel rate all sit at career lows, making for a big jump in his expected stats, and giving him the results that have shown up for Wilson this season.

The success of Wilson has forced him into the Brewers' future plans post-2023. The long reliever is one of the most undervalued positions in all of baseball, and Milwaukee has relied on him to give them a reliable presence in that role. Due to Wilson's low service time of just over 2 years entering 2023, the Brewers still have all three arbitration years remaining on his contract. He is out of options, so he would need to stay on the MLB roster to stay put in the organization

Relievers have the most variance in baseball for a position, and while his 3.91 xERA compared to his 2.59 season ERA shows some regression to come, Wilson has been productive all season, and the Brewers hope that he can continue to make an exponential rise after a non-linear start to his career. If he can do so, he will have a role in Milwaukee's bullpen for the near future, and could be extremely valuable to the team over at least the next three seasons.