The radar gun at American Family Field didn't just register a number on Friday night; it registered a shift in the physics of professional baseball. In the first inning, Milwaukee Brewers starter Jacob Misiorowski fired a fastball toward Cubs center fielder Pete Crow-Armstrong that clocked in at 105.5 mph.

It wasn't just a heater. It was a record-breaker. That pitch stands as the fastest ever recorded by a starting pitcher in the pitch-tracking era, which dates back to 2008. To put that velocity into perspective, it matches the mark set by reliever Ben Joyce in 2024 and sits just behind the legendary 105.8 mph and 105.7 mph pitches thrown by Aroldis Chapman over a decade ago.

The Limit of Human Velocity

For most of baseball history, a starting pitcher hitting 100 mph was a rare, headline-grabbing event. Misiorowski, however, is treating triple-digit velocity as his baseline. His first pitch of the night hit 103.1 mph. The next was 104.3 mph. By the time he reached the third, he had shattered his own record of 104.5 mph, set just two weeks prior against the Philadelphia Phillies.

"Where does it stop?" Brewers manager Pat Murphy asked reporters after the 6-2 win. "I think there's a limit there."

Misiorowski, only 24, seems unconvinced that he has found it. When asked if 106 mph is within reach, he didn't hesitate. "I definitely think it's possible," he said. "Science says you can hit 108. Someone eventually is going to hit it. If that's me, cool."

More Than Just a Radar Gun Stunt

While the velocity is the story that will circulate on social media, the more significant development is the 1.45 ERA Misiorowski has maintained through his first 16 starts. That mark is the third-lowest for a pitcher through 16 starts in the last 50 years, trailing only Nolan Ryan’s 1.29 in 1981 and Trevor Rogers’ 1.43 last season.

He isn't just throwing hard; he is surviving deep into games. On Friday, he logged six innings and threw a season-high 107 pitches. Even with his final delivery of the night—a 102.8 mph fastball that struck out Ian Happ with the bases loaded—he showed no signs of the fatigue that typically plagues power pitchers.

The Cubs' Tactical Response

Chicago’s lineup didn't just roll over. They understood that they couldn't catch up to the heat, so they opted to grind. The Cubs forced Misiorowski to work, drawing four walks and driving up his pitch count.

"They had a game plan coming in to battle me and foul s--- off," Misiorowski admitted. "They stuck with it. More power to them."

Despite the traffic on the bases, the Brewers' offense eventually provided the necessary support. Garrett Mitchell’s two-run homer in the sixth inning broke a 1-0 deficit, and the team never looked back. It was a complete performance, but one that will be remembered solely for the first-inning display of raw, unprecedented power.

Key Takeaways

  • Historic Velocity: Misiorowski’s 105.5 mph pitch is the fastest ever recorded by a starting pitcher since the pitch-tracking era began in 2008.
  • Elite Consistency: Beyond the speed, his 1.45 ERA through 16 starts puts him in the company of legends like Nolan Ryan.
  • The Ceiling: The 24-year-old believes 106 mph is attainable, suggesting that the upper limits of human pitching velocity are still being tested.

As the season progresses, the league will continue to adjust. For now, Misiorowski remains the most fascinating experiment in baseball. He is proving that the traditional constraints on starting pitchers—the idea that you must sacrifice velocity for longevity—may no longer apply. His next start will be scrutinized not just for the win-loss column, but to see if the radar gun needs to be recalibrated once again.