Jacob Misiorowski, the Milwaukee Brewers’ young ace, is the same height as Aaron Judge, the New York Yankees’ hulking slugger, and about half his size. When they faced each other, on May 8th, it was like seeing Paul Bunyan swing his axe at a sapling. Except, in this case, the sapling could throw a fastball at more than a hundred miles per hour.

Judge came to the plate against Misiorowski three times that night. In their first matchup, in the top of the first inning, Judge started the at-bat by taking a strike. It was the seventh straight fastball Misiorowski had thrown, all for strikes, all above a hundred m.p.h. Then Judge took another. Misiorowski’s third pitch, clocked at 103.1 m.p.h., just missed the low outside corner. Was Judge looking for a fastball again on the next one? It wouldn’t have mattered: the pitch came in at 103.6 m.p.h, the hardest pitch thrown by a starting pitcher since the league started recording speeds via Statcast, in 2008. Judge lined it feebly into the glove of an outfielder. He struck out in the fourth, and again in the sixth, Misiorowski’s tenth punch-out of the night. Misiorowski also struck out the next batter, Cody Bellinger. Since 2008, starting pitchers have thrown only three pitches of a hundred and three miles per hour or more, including one that Misiorowski threw in his previous start, against the Washington Nationals. Facing the Yankees, Misiorowski threw ten such pitches.

Misiorowski is twenty-four years old, though his concave chest and the softness around his jaw make him look younger. He’s come of age in an era in which triple-digit speeds are no longer rare. Teams covet velocity; it’s now more common to see a pitch break a hundred than to see a double play. The obsession with a hundred has something to do with our attraction to round numbers, but, at that speed, every mile per hour does make a difference. Last season, fastballs thrown at ninety-eight miles per hour or faster induced a strikeout rate of nearly thirty per cent; fastballs thrown at ninety-seven m.p.h. or below produced a rate of only seventeen per cent. Hitters bat less than .200 against fastballs thrown faster than a hundred m.p.h., compared with .237 off fastballs thrown at ninety-eight and .267 against fastballs thrown at ninety-five, which was formerly the standard for good heat.

There have been power pitchers throughout the game’s history, of course: Bob Feller, Bob Gibson, Walter Johnson. Randy Johnson once accidentally exploded a bird with his fastball. Nolan Ryan threw a hundred miles per hour, on his way to a record 5,714 strikeouts. But Ryan was an outlier. No one else was doing it.

Now better training methods and new technology—in particular, camera and radar networks that can precisely measure a ball’s movement and create three-dimensional models of a pitcher’s mechanics—have helped pitchers learn to throw harder and harder. They spend their off-season at special baseball facilities training their arms—or, more often, building up their legs, which is where most of the power comes from. In 2008, there were just two hundred and fourteen pitches thrown at a hundred miles per hour or more. In 2025, there were 3,701 of them.

This has led to something of a crisis, or possibly two. For one thing, that extra speed—plus a spike in spin, which has allowed pitchers to throw harder while also making the ball swerve, dive, and kick—has given pitchers an even greater advantage over batters than before. According to Statcast, there were nearly twelve thousand fewer balls hit in play during the 2025 season than in 2008, and the lack of offense has made the game a little less exciting. More worrisome, though, is what throwing at maximum effort does to a human arm. Tendons and ligaments remain weak links, and the harder you throw, the more torque on your elbow. Consequently, the number of arm injuries has exploded. More than a third of major-league pitchers have ruptured their ulnar collateral ligament, requiring so-called Tommy John surgery, which can take more than a year to recover from. And those who haven’t had it yet can expect to. Teams basically price such injuries into their expectations for a young pitcher. They can do that because hard-throwing pitchers are becoming more and more fungible. When one goes down, there’s always another.

Misiorowski, a product of Crowder College, a junior college in Neosho, Missouri, threw forty-three pitches at a hundred miles per hour or faster during his recent outing against the Nationals. He threw another forty-one against the Yankees, including ten straight. And last week, facing the San Diego Padres, he threw forty triple-digit fastballs again. Batters can expect him to throw a four-seam fastball: he uses that pitch more than sixty per cent of the time.

That’s another thing that sets him apart from most top starters. Tarik Skubal, the two-time American League Cy Young Award winner, can throw about as hard as Misiorowski, but Skubal uses his four-seam fastball less than forty per cent of the time. Modern technology lets pitchers experiment with grips and spins to create gnarly movement and ambush batters with off-speed action. Max Fried, the Yankees’ ace, throws seven different pitches. So does Shohei Ohtani. Misiorowski throws just three pitches with any regularity, but he throws his four-seam fastball so hard that the element of surprise is hardly necessary. His fastball not only arrives faster than the blink of an eye but also comes in at a tricky angle. When Misiorowski pitches, his muscular legs take a long stride down the mound, and then his skinny right arm, which is as loose as a whip, follows. (He’s built like a centaur.) As a result, he releases the ball closer to home plate than any other pitcher. And his length lets him get low. That, along with the angle of his arm—his arm slot, in baseball terms—adds another layer of deception. His fastball comes in flatter than it looks to the batter, creating the illusion that it’s rising—a ball that appears to be at the top of the zone out of his hand might actually be a few inches above it, tempting batters to swing under. All that “makes for a tough day,” as Judge said after facing the young pitcher. Judge called Misiorowski’s fastball one of the best he’d ever seen.

The average speed of his fastball this season, hovering around 99.6 m.p.h., would be the highest for any qualified starter in the pitch-tracking era, by far, if he can keep it up. What’s astonishing about Misiorowski during this stretch is his consistency. Most of the hardest-throwing pitchers now are relievers, who can empty their tanks on each pitch without having to keep anything in reserve for later innings. Misiorowski, meanwhile, enters the first inning as though it were the ninth. He holds nothing back. And yet he’s still throwing fastballs at a hundred and two miles per hour in the sixth inning, for strikes.

Will it last? Can it? The human body was not built to withstand those kinds of demands—or most bodies, anyway. There are always exceptions. Ryan, after all, pitched more than five thousand innings without blowing out his arm. But, more and more, the incentives are for pitchers to push the limits until something breaks—whether it’s a limit or a ligament. Misiorowski was so impressive in the first half last season that he made the All-Star team after just five appearances, but he faded badly in the second half, and his earned-run average exploded. Misiorowski has been pitching deeper into games so far this season—or at least as far as any carefully managed young player is allowed to go these days. But he exited two of his previous three games with cramps. It’s common for velocity to drop as the season goes on and fatigue sets in—and fatigue is linked to an increased chance of injury.

That’s the game of roulette that pitchers always play these days. It should make me, as a viewer, queasy: the eighth pitch of the first inning isn’t worth risking a catastrophic injury for. But there’s something primal about a fastball. Athletes are always getting bigger, stronger, and faster, and doing ever more incredible things. And yet I never tire of seeing that blur of pure speed. ♦