The record books may need to be written in pencil.
On a June afternoon at Wrigley Field, Milwaukee Brewers pitcher Jacob Misiorowski threw a 105.5 mph fastball — a number that quietly reshapes what we believe human arms are capable of. In tying Ben Joyce's record for the hardest pitch ever thrown by a starting pitcher, Misiorowski has entered a conversation long thought closed, one defined by Aroldis Chapman's seemingly untouchable all-time mark of 105.8 mph. What unfolds now is less a sports story than a meditation on limits — and what happens when someone refuses to accept them.
- A single fouled-off pitch at Wrigley Field registered 105.5 mph, instantly tying a record most assumed would stand for years.
- Misiorowski has now thrown two historically elite fastballs within weeks, suggesting this is not a fluke but a pattern in motion.
- The all-time record — Chapman's 105.8 mph — now sits just 0.3 mph away, a margin that feels less like a wall and more like a dare.
- Baseball's record books, written as if in permanent ink, are suddenly being reconsidered in pencil.
- The baseball world watches Misiorowski's early-inning velocity with growing anticipation, knowing the next record-breaking pitch may already be loaded in his arm.
Jacob Misiorowski was on the mound at Wrigley Field, two strikes on Cubs leadoff hitter Pete Crow-Armstrong, when he threw a fastball that disappeared into foul territory down the third baseline. Unremarkable in outcome — extraordinary in velocity. The scoreboard read 105.5 mph.
It was not his first brush with history. Just two weeks prior, Misiorowski had thrown a 104.5 mph fastball past Philadelphia's Kyle Schwarber, setting the MLB record for the hardest pitch ever thrown by a starting pitcher. In that same at-bat, he had repeatedly crossed the 103 and 104 mph thresholds, as if announcing his arrival in a different tier of the sport entirely.
With the Wrigley fastball, Misiorowski tied Ben Joyce of the Los Angeles Angels, who had matched that 105.5 mph mark in 2024. The two now share the starter record. But the all-time crown still belongs to Aroldis Chapman of the Red Sox, whose pitches of 105.7 and 105.8 mph have long felt like monuments rather than marks.
What separates Misiorowski's story from a single remarkable moment is the trajectory. He appears sharpest early in games, when mechanics and freshness align — both record-setting pitches came against leadoff hitters. The pattern implies intention, or at least potential. Chapman's record, once the kind that seemed destined to outlast careers, now looks like a target. The gap is 0.3 mph. The record books, it turns out, may need to be written in pencil.
Jacob Misiorowski was standing on the mound at Wrigley Field on a June afternoon, facing Cubs leadoff hitter Pete Crow-Armstrong with two strikes already in the count. The pitch he threw was unremarkable in its placement—a fastball that Crow-Armstrong fouled off down the third baseline. What made it noteworthy was the number that appeared on the scoreboard: 105 mph. The official reading was 105.5.
This was not Misiorowski's first brush with the record books. Just two weeks earlier, the Milwaukee Brewers right-hander had thrown a 104.5 mph fastball past Philadelphia's Kyle Schwarber, setting what was then the MLB record for the hardest pitch ever thrown by a starting pitcher. In that same at-bat against Schwarber, Misiorowski had unleashed multiple pitches exceeding 103 mph, with several crossing the 104 mark. The velocity was so startling that it seemed to announce something: this pitcher was operating in a different realm.
Now, with his 105.5 mph fastball against the Cubs, Misiorowski had tied Ben Joyce of the Los Angeles Angels, who had thrown a pitch of identical velocity back in 2024. The two men now shared the record for the hardest fastball ever recorded by a starter. But the all-time mark remained out of reach—for now. Aroldis Chapman, the Red Sox pitcher, still held that distinction with two pitches clocked at 105.7 and 105.8 mph.
What made Misiorowski's trajectory remarkable was not just the single pitch, but the pattern. He appeared to be at his most dangerous early in games, when his arm was fresh and his mechanics were sharp. The Schwarber pitch had come in the leadoff spot, much like the Crow-Armstrong fastball. If the trend held, and if Misiorowski continued to push his conditioning and mechanics, the gap between his current velocity and Chapman's all-time record seemed less like a barrier and more like a target.
The baseball world had grown accustomed to seeing fastball speeds creep upward over the past decade, but Misiorowski's recent performances suggested something different—not incremental progress, but a genuine leap. Whether through training, biomechanics, or simply the natural variance in how hard any given pitcher could throw on any given day, he had entered a conversation that had seemed settled. Chapman's 105.8 mph fastball, thrown years earlier, had the feel of a record that might stand for a generation. Now, with Misiorowski throwing 105.5 twice in as many weeks, that assumption looked premature. The record books, it seemed, would need to be written in pencil.
Citações Notáveis
Misiorowski appears to be at his best when fresh early in games, suggesting his elite velocity may be repeatable.— Reporting analysis
A Conversa do Hearth Outra perspectiva sobre a história
What makes Misiorowski different from other hard throwers we've seen?
The consistency at the top end. Most pitchers touch 100 once or twice a season. He's doing it regularly, in game situations, against major league hitters.
Is this just a fluke—two great pitches in two weeks?
Possibly. But the pattern suggests otherwise. He's hitting these velocities early in games, when he's fresh. That's repeatable if the conditioning is there.
Chapman threw 105.8 years ago. Why hasn't anyone matched that until now?
Chapman was a relief pitcher, fresh every time. Starters face different demands. Misiorowski is doing this as a starter, which changes the conversation about what's sustainable.
Can he actually throw 106?
If the trajectory holds, yes. But there's always a ceiling. The question is whether he's found his or if he's still climbing.
What does this mean for baseball?
It means the sport's physical limits are still being tested. We thought we knew where the fastball topped out. Misiorowski is suggesting we were wrong.