Jacob Misiorowski Has Fast-Tracked His Way to Becoming an Ace

When he broke in with the Brewers last season, Jacob Misiorowski was tough to miss, unless you were a hitter trying to catch up to his ridiculous velocity. The gangly 6-foot-7 righty announced his presence by reaching 100.5 mph on his first major league pitch and topping out at 102.2 mph in five no-hit innings against the Cardinals in Milwaukee on June 12. He followed that up with six perfect innings against the Twins before yielding a walk and a homer, and was named to the National League All-Star team as an injury replacement after just five starts. He soon leveled off, and finished with comparatively unspectacular numbers — he was an afterthought in the NL Rookie of the Year voting — but this season is a different story. The 24-year-old righty has dominated hitters like a true ace, and has improved in practically every important statistical category.

Misiorowski’s latest outing, once again facing the Cardinals in Milwaukee, was both a gem and an awe-inspiring display of firepower. Monday’s effort began with an unprecedented, if somewhat unproductive, barrage of six consecutive four-seam fastballs to JJ Wetherholt, each clocked at 103.0 mph or higher — but four of them were well outside the strike zone, resulting in a walk:

Misiorowsi overcame the leadoff walk, escaping the inning by throwing just seven more pitches on back-to-back three-pitch strikeouts of Iván Herrera and Alec Burleson, then a first-pitch groundout by Jordan Walker. In fact, he retired 15 straight hitters after the walk, again completing five no-hit innings before yielding a leadoff single to Pedro Pagés in the sixth. The Cardinals turned that into a run after speedster Victor Scott II replaced Pagés on a forceout, took third on a single to right field by Wetherholt, and scored on a grounder by Herrera, but Misiorowski stuck around to complete the sixth and seventh innings before departing with a 4-1 lead. The Brewers won, 5-1.

That run ended Misiorowski’s scoreless streak at 29 1/3 innings, more on which momentarily, but first, consider his velocity in that outing. Misiorowski reached 100.0 mph with his four-seam fastball 57 times, 10 more than any other pitcher in a single start in the pitch-tracking era (dating back to 2008); the Reds’ Hunter Greene held the previous record with 47 on September 17, 2022, also against the Cardinals. Misiorowski also set a tracking-era record by reaching 101.0 mph 40 times, besting Greene’s 33 in that same start, and matched another tracking-era record — and his own personal best — by reaching 102.0 mph 22 times (he also did so on May 8 against the Yankees). He reached 103.0 mph nine times, one shy of his May 8 total and three short of Aroldis Chapman’s single-game record, set on September 19, 2016 for the Cubs against the Reds.

Finally, Misiorowski’s 101.1-mph average velocity on his four-seamer matched his personal best from May 8. The only higher average from a starter in the pitch-tracking era comes with an asterisk, as the Angels’ Ben Joyce averaged 101.2 mph on 11 heaters in a two-inning start as an opener — his only start among 48 major league appearances — on June 16, 2024 against the Giants.

And yes, that velocity matters. On the 311 pitches where Misiorowski has reached 100 mph this season (31.2% of his total number of pitches, and 50.1% of his four-seamers), batters are hitting and slugging just .116, while whiffing on 49.7% of their swings. On Monday, the Cardinals went 1-for-15 with a 43.3% whiff rate against those triple-digit heaters, with Wetherholt’s single the lone blemish.

“That’s what I do, I throw hard,” said Misiorowski afterwards. His four-seamer is averaging 99.8 mph, tops among qualified starters and up half a tick over last season. But it’s not just about the velo; he has improved on virtually every statistical front after an offseason spent focusing on building strength in his lower body. The man did not skip leg day; according to MLB.com’s Adam McCalvy, his pant size increased from 36 to 38. “Last year I bought all new jeans,” he said. “Now it’s like, they’re gone.”

Prior to Monday, Misiorowski had last allowed a run in the sixth inning on April 25. Monday’s start was his second time this month taking a no-hitter into the sixth; against the Nationals on May 1, he departed due to a right hamstring cramp after throwing 5 1/3 hitless innings. His 12 strikeouts against the Cardinals matched his career high, set last July 8 against the Dodgers, and marked his fifth time reaching double digits this season and third this month. Arguably, he’s outpitched the Phillies’ Cristopher Sánchez, who’s riding a major league-high 37 2/3-inning scoreless streak, including 32 innings this month:

The sinkerballing Sánchez has made one fewer start and has still totaled more innings by pitching deeper into games. He’s also got the lower walk rate of the pair, but Misiorowski has the edge in most other categories, and it probably doesn’t hurt that he’s playing in front of a better defense. Not that one yet-to-be-completed month is going to decide the NL Cy Young race or that these two are the only candidates, particularly when Shohei Ohtani is carrying an 0.73 ERA.

Still, statistically, almost nobody is beating The Miz these days. He leads all major league starters in strikeout rate (40.3%), strikeout-to-walk differential (32.7%, higher than every starter’s strikeout rate save for Dylan Cease’s 35.7%), and xERA (2.15). He also leads the NL in FIP (1.89) while ranking second in the league in both ERA (1.83) and WAR (2.6) behind Sánchez (Ohtani’s 49 innings leaves him six shy of qualifying for the ERA title). He’s done all of this while lasting at least five innings in all 11 of his starts, and even while becoming the first pitcher to reach 100 strikeouts this season, he’s surpassed 100 pitches just once, with 101 on April 7 against the Red Sox. Four of his five double-digit strikeout games required fewer than 100 pitches; nobody else has more than two such games this season.

All of this is a huge step forward from his rookie season, which Misiorowski finished with a 4.36 ERA and 3.62 FIP in 66 innings spread over 14 starts and one relief appearance. After taking a comebacker off his left shin on July 28 and landing on the injured list, he put up a 6.06 ERA and 4.11 FIP in 32.2 regular season innings, lasting five innings in just three of his six starts. With his innings total in uncharted territory (129.1, including his frames at Triple-A Nashville), he did pitch well in a bulk relief role in the postseason, totaling 12 innings in three appearances, with a 1.50 ERA and 2.30 FIP, but it wasn’t enough to prevent the Brewers from being swept out of the NLCS by the Dodgers.

Not only has Misiorowski’s fastball gotten faster, its arm-side movement has increased from 9.4 inches to 11.3. Among the pitchers whose four-seamers are averaging 98 mph or higher, only a small handful are getting at least 10 inches of horizontal movement:

Hitters are whiffing against Misiorowski’s heater more often, and doing less damage against it — and the same is true for his slider and curve:

While Misiorowski’s superhuman velocity feats are the talk of baseball, according to Statcast the run value of his slider is actually higher than that of his heater: The former is a major league-high 10 runs above average, while the latter is in a virtual tie for fourth at eight runs above average.

Whether that slider is actually a slider appears to be a point of contention, albeit one that offers some insight into Misiorowski’s advances. According to Jack Stern of Brewers Fanatic, broadcast analyst Vinny Rottino reported that Misiorowski and the Brewers consider his slider to be a cutter, and Stern himself made his own case for that classification last December. Pitch Info shows that he threw the pitch 24.3% of last year, matching Statcast, and that he’s now throwing both that pitch and a true slider:

Similarly, Stern cited a recent TJ Stats post separating the cutter and the slider (though the two pitches aren’t separated on the TJ Stats site):

Per @VinnyRottino on the broadcast, Misiorowski and the Brewers consider his "slider" a cutter and have added a true slider as a separate pitch. https://t.co/mjNWx7fgP0 pic.twitter.com/NavKTBEEE1

— Jack Stern (@ByJackStern) May 20, 2026

The Pitch Info-driven game-by-game usage graph from Brooks Baseball shows one stray slider last year (matching up with Pitch Info’s classification of a lone sweeper) and only intermittent usage of the new pitch, first in March, and then in four of Misiorowski’s last five starts:

Not all of the usage and movement numbers line up from source to source because pitch classification is a fuzzy thing. While still referring to the pitch as a slider, on his Substack “Lance’s Pitchers Notes,” Lance Brozdowski highlighted data from Monday’s outing as differing from Misiorowski’s previous slider:

The more interesting thing to me in this outing is that his slider shape had a lot more drop than it’s had at any point this season, even though he only threw 16. This shape averaged 3.5″ vertical break and 4″ glove-side movement at 93 mph, very different from his season average of 7.4″ vertical break and 1″ glove-side movement at 94.6 mph. This is likely more of a hand manipulation thing to generate more depth and sweep on the offering. I’d guess it’s intentional rather than accidental, given it’s not happening because of a lower slot or cutting his four-seamer more.

I wrote two weeks ago about how Misiorowski should throw a sinker. In that piece, I also talked about how this breaking ball shape is kind of in between a cutter and a bullet slider given how hard he throws it. We’re now seeing it take more of the true slider route if its movement stays below 4″ vertical break. I’ll emphasize again that the reason it’s so easy to love Misiorowski long term is that he’s succeeding with a fastball-heavy approach when there are clear paths to more shapes (sinker, true cutter for lefties, true slider to righties, and more curveballs).

Adding a new pitch would certainly help account for Misiorowski’s leap forward. Overall, his whiff rate has jumped from 29.7% to 39%, and with it, both his strikeout and walk rates have improved; the former is up 8.5 percentage points (from 31.9% to 40.3%), the fifth-largest jump among pitchers with at least 60 innings last year and 30 this year:

That’s a nice little list full of guys breaking out to one degree or another; our staff has already done some early check-ins on what Bradley, Hancock, Martin, Roupp, and Soriano are doing differently this season. Misiorowski was starting from a much higher strikeout rate than any of them, and now he’s in the stratosphere; among pitchers who had at least a 25% strikeout rate last year, the second-largest jump is by Cease, who just missed the cut for the table above with a 5.9-point increase (from 29.8% to 35.7%).

Meanwhile, Misiorowski has cut his walk rate from 11.4% to 7.7%, the fifth-largest drop using the same cutoffs (Cam Schlittler’s 5.5-point drop, from 10.2% to 4.7%, ranks first). Misiorowski’s 12.1-point improvement in strikeout-to-walk differential is second only to Martin’s 13.1-point improvement (from 9.3% to 22.4%) on a leaderboard that includes five other pitchers from the above strikeout rate table.

Even while striking out more hitters, Misiorowski has become more efficient, cutting his pitches per plate appearance from 4.28 to 4.01. Batters are chasing more often (31.7%, up from last year’s 28.6%) and making less contact (a major league-low 64%, down from 73.7%). And when they do make contact, it’s rarely hard contact:

Note the drop in average launch angle; Misiorowski has boosted his groundball rate from 34.9% to 44.4%. He’s also cut his pulled air rate from 17.8% to 12.1%. Percentile-wise, his average exit velocity allowed has climbed from the 57th percentile to the 86th, his barrel rate from the 59th percentile to the 94th, and his hard-hit rate from the 72nd percentile to the 83rd.

All told, there doesn’t appear to be an area of major importance where Misiorowski has regressed from his solid rookie season. While it’s too early to handicap the NL Cy Young race, particularly given the possibility that the Brewers are likely to be mindful of increasing Misiorowski’s innings total too sharply, he’s pitching like someone who will be part of that conversation.