Alex Vesia didn't know he possessed a superpower. A late-round draft pick with a few cups of coffee in the big leagues, Vesia had neither great numbers nor notable prospect status. He was Clark Kent all the way.

But when the Los Angeles Dodgers traded for the lefty reliever in 2021, they practically handed him a mask and a cape.

"They asked me, 'Do you know what the vert is on your fastball?'" Vesia said. "I was like, 'What are you talking about?'"

Induced vertical break -- that's what the Dodgers were talking about.

For more than a century, it was the hidden secret behind some of the game's greatest fastballs, an ability so powerful that it was long considered a myth, dismissed by science but recognized by scouts. Their reports told of fastballs with "life," of four-seamers that turned "invisible." These pitches could rise like ghosts, and hitters would swing right through them. This was more than velocity. These pitches were special, and could seem to move upwards in some immeasurable way.

Then, roughly a decade ago, curious minds began to gather fresh data and learn the truth behind the rising fastball.

It was real, in a sense. When a ball doesn't fall at the rate our brains expect it to, it looks to the human eye like it is rising. That perception of rise is created by a ball spinning on a proper axis, generating lift from the seams, fighting gravity as it crosses the plate. The phenomenon came to be known as induced vertical break, a discovery that has changed everything about modern pitching.

"I like to call it the Gerrit Cole Era," San Diego Padres starter Michael King said. "That's when everybody started throwing that four-seamer at the top of the zone."

Today's pitchers throw bullpen sessions and make a game of guessing each fastball's "vert," and discussing its "ride," another term for the phenomenon. Most big leaguers produce roughly 16 inches of induced vertical break with their four-seam fastballs, but a select few can routinely get to 20 inches.

Vesia has averaged 21 inches this season, the most in the majors. He led the league in induced vertical break last year, too. His velocity is pedestrian -- he sits 92 to 94 mph -- but opponents are hitting .167 against his fastball. In five seasons with the Dodgers, Vesia has a 2.61 ERA with more than 12 strikeouts per nine innings. He pitched in four of five World Series games last year and got the save in Game 2.

"When I throw the ball down the middle and a guy swings through it, it makes sense," Vesia said.

It makes sense because big-league hitters aren't programmed to hit a fastball with that much induced vertical break. They've faced thousands of fastballs, and when they see one at a certain speed from a certain arm angle, they're trained to anticipate a certain path across the plate. A pitch with above-average carry changes that calculus.

"When I see 18 to 20 (inches of induced vertical break), I have to swing two balls above it," Boston Red Sox outfielder Rob Refsnyder said.

Easier said than done. And the same could be said for induced vertical break itself. Not every pitcher can create it with ease, and not every pitcher needs to, but the ability to manipulate and understand vertical movement -- to determine who has it, how to generate it and what to do with it -- has revolutionized the game.

Fastballs aren't breaking balls, but they aren't necessarily straight, either. Fastballs can move down (sink), to the glove side (cut), or to the arm side (run). And yes, in a manner of speaking, fastballs can rise. A rising fastball is often labeled an illusion -- the ball can't literally move up -- but pitches spin, and balls have seams, and the Magnus effect creates lift. Fastballs can, and almost always do, cross the plate higher than gravity says they should.

"The tilt, or the spin direction of the ball, the grip," Red Sox director of pitching Justin Willard said, "all of these things factor into how much ride or carry or lift that you're creating."

Pitching coaches use something called a short-form movement plot to measure pitch movement as if gravity didn't exist. (In theory, a seamless ball thrown with no spin would have zero inches of induced vertical break.) Pitchers who generate more than 20 inches of induced vertical break can throw a fastball that seems destined for the letters but finishes closer to the shoulders, or a fastball that seems headed toward the dirt but nips the bottom of the zone.

Here, Logan Gilbert throws a slider with zero/zero movement on the left, and a fastball of his with 16 inches of vert on the right, followed by an overlay of the two to see what 16 inches of vert looks like in the real world.

It's deception through movement, not all that different from a biting slider or a darting changeup. Induced vertical break defies a hitter's expectations, which is at the heart of pitching.

"It's essentially, how weird can you make your arsenal?" Willard said.

There's not much weirder than a pitch that seems to do the impossible. The notion of a rising fastball predates any scientific explanation. Hal Newhouser, the Hall of Fame lefty, wrote a nationally syndicated newspaper column in 1949 explaining the purpose of a windup, the shapes of various pitches and the value of pitching to different locations.

"A rising fast ball," Newhouser wrote, "is pitched from the waist up. This usually results in long flies or pop-ups."

Walter Johnson, Bob Feller, Sandy Koufax, Tom Seaver, Jim Palmer, Nolan Ryan and countless others were said to throw rising fastballs even as scientists occasionally clarified that such a pitch was physically impossible.

"I would invite them, at their leisure," Pittsburgh Pirates third base coach Rich Donnelly said in 1993, "to bat against Roger Clemens, Rob Dibble and Dwight Gooden and then tell me it's an optical illusion."

A St. Louis Post-Dispatch story in 1990 noted that, while some physicists felt that extreme velocity created the appearance of rise, no less an authority than Bob Gibson "insisted that the aerodynamics of air working on a baseball's raised seams can make the thing rise."

Gibson had the right idea.

Technology now exists not only to measure induced vertical break, but also to pinpoint the various factors -- velocity, grip, arm slot, spin rate, spin axis, etc. -- that create and amplify it. Pitchers and organizations game plan around the ability to create lift, either tweaking a delivery to maximize it, or changing the pitch mix of pitchers who simply don't have it. Texas Rangers starter Nathan Eovaldi has long been one of baseball's hardest throwers, but his fastball creates only average vertical break. His success has come from changing speeds and mixing pitches, not firing 97-mph fastballs at the top of the zone.

"I still try going up," Eovaldi said. "It's just I feel like sometimes they foul them off. ... Sometimes I just scratch my head."

About a decade ago, a combination of technology, data and curiosity eliminated some of that head scratching and found the truth in the mystery.

It was late 2013, maybe 2014, when Tampa Bay Rays minor league pitching coordinator Kyle Snyder was introduced to a man named Josh Kalk. Snyder was a former first-round pick whose big-league career had ended at age 30 with a 5.57 ERA. Kalk was a former math and physics professor who'd gotten into baseball with a job in the Rays' analytics department.

The pair were still getting to know each other when Kalk walked into a Longhorn Steakhouse in Princeton, W. Va., then the home of the Rays' short-season affiliate. He carried a stack of papers showing PITCHf/x plots for various pitchers Snyder had coached the previous two years.

There was something else: The top page contained data on Snyder himself.

For a decade in pro ball, Snyder had tried to unlock his own potential so that he could stick in the major leagues. With a few charts and numbers over dinner, Kalk laid bare the missed opportunities.

"The most powerful moment of my career," Snyder said. "He goes, 'You threw sinkers. You should have thrown four-seamers. Your slider was better than your curveball. Your curveball was too slow.'"

Right there on paper, five years too late, was the career-saving information Snyder needed.

"It was such a powerful moment for me in terms of how tech and science was going to change baseball and pitching development," Snyder said. "I'll never forget that moment. It changed the course of my career, and I owe a ton -- an absolute ton -- to Josh Kalk."

Few, if any, have done more than Kalk to shape the modern understanding of pitching. He is quick to say he wasn't the first or only person to do this work, but others tout his influence. The pitch-tracking era was still young when Kalk began mining underlying metrics for a better understanding of what makes pitches effective. Under progressive thinkers such as Snyder and former general manager Andrew Friedman, the Rays applied Kalk's analysis to build an organizational reputation for elite pitching.

Well before the advent of Statcast, Kalk studied numbers from the league, which made league-wide PITCHf/x data publicly available in 2008, popularizing the notion of spin rate. But the online PITCHf/x data presented in Javascript was limited. Kalk, whose academic background includes a minor in computer science, figured out how to access the underlying XML file. That, it turned out, was the motherlode.

"You looked at the entire sample of the data," Kalk said, "and then you were able to see some indications of pitchers that had movement that looked like this (and) were performing better than pitchers that had movement that performed like something else."

Spin rate was the buzzword for much of the 2010s, but Kalk realized movement was the Holy Grail.

"Induced vertical break has always been the second-most important metric (after velocity)," Kalk said. "I don't know whether some teams got obsessed with spin rate in reality or whether that was just a talking point, but induced vertical break outperforms spin rate in every pitching metric that you want to look at. And I'm free saying that right now because everybody knows that."

Ten years ago, such analysis was still proprietary; Kalk instructed Rays coaches to say "spin rate" in interviews because he didn't want other organizations to pick up on Tampa Bay's true priority. The Rays weren't chasing spin. They were chasing movement, which doesn't come from spin alone.

"We're after the break value, right?" Snyder said. "We're not after the ingredients that could potentially influence the break value."

Does having significant ride on your fastball mean you're a great pitcher? No. But having a couple previously undervalued relievers sitting atop the leaderboard this year does underline the value of good fastball shape.

Kalk is now vice president of baseball operations strategy and innovation for the Minnesota Twins, Friedman is president of baseball operations for the defending champion Dodgers and Snyder is in his eighth season as the Rays' major-league pitching coach.

From a stack of papers in a chain restaurant in West Virginia to the video boards of most big-league ballparks, induced vertical break is everywhere, if you know where to look. Today's pitchers talk about "vert" nearly as often as they talk about "velo." Padres pitching coach Ruben Niebla, who, like Snyder, is considered one of the better instructors in the game, said he often reminds his pitchers of their movement readings between innings.

"This is the first thing science did, in my opinion, to really influence the game," Snyder said. "R&D departments started to get really built out, recognizing the importance of some of these things ... Not to simply tell a guy, 'Stay behind the ball,' but put drill packages together to help him be able to understand appropriate steps of how to achieve that."

Now, players arrive in the big leagues with prior knowledge. Kyle Boddy, the founder of Driveline Baseball and a special advisor to Red Sox chief baseball officer Craig Breslow, said he rarely needs to explain the concept of induced vertical break.

"I don't have to anymore," Boddy said. "Pitchers aren't dummies."

When Red Sox starter Lucas Giolito changed his mechanics in 2019, the induced vertical break on his four-seam fastball improved by 2 1/2 inches. He ditched his sinker, threw his four-seamer 55 percent of the time and enjoyed the best season of his career.

Atlanta Braves reliever Dylan Lee also threw two-seamers when he was younger, and he spent years in pro ball trying to master a curveball. It got him released by the Marlins. He's since built an excellent career throwing mostly four-seamers and sliders out of the Braves bullpen. Even when Lee tries to reduce the vertical break on a changeup and make it sink, he finds his arm angle just isn't right for it. Lee's delivery is built for pitches with carry.

San Diego Padres reliever Jeremiah Estrada similarly can't explain his tendency for vertical movement. He grew up trying to mimic Pedro Martinez's changeup, but otherwise did what felt comfortable. He wound up with mechanics that naturally spin a fastball on just the right axis for maximum vert.

"To this day, I'm still doing the same thing," said Estrada, the hardest thrower among the majors' top 25 pitchers in terms of four-seam induced vertical break. "Just go out there and throw it."

Since the beginning of 2024, Estrada owns the single fastball with the most recorded vert: 27 inches. He recorded it on this strikeout in June 2024.

The four-seam fastball, amid a decades-long decline in usage, remains the majors' most popular weapon. According to Statcast, four-seamers account for almost a third of all pitches thrown this season. The next-closest pitch is the slider, at 22.3 percent.

This helps explain Kalk's belief that a pitcher's fastball shape is akin to a fingerprint. It's ingrained and, for many, almost impossible to change.

"What led me to believe that," Kalk said, "was a lot of attempts to try to change that and few successes. Not zero but few."

It's easier, Kalk said, for a pitcher to learn a new changeup, or a slider or sweeper. Fixing a poor fastball without making drastic adjustments tends to present a far greater challenge, even for the most talented pitchers on the planet.

Some pitchers don't need extreme vertical break to create four-seam deception. Lower arm slots naturally create less vertical movement -- Pittsburgh Pirates phenom Paul Skenes, for example, produces a modest amount of induced vertical break -- but those arm slots also create different expectations for hitters. Fifteen inches of induced vertical break from a 20-degree arm slot could have the same effect as 20 inches of vertical break from an over-the-top delivery. Think Josh Hader, or Zack Wheeler. The deception is what matters.

The true 'dead zone' is the vert you'd expect given a certain arm slot. You can then express 'good' ride as vert over that expectation, as public analyst Alex Chamberlain does on his leaderboards with "Dead Zone delta" stats. Here are the leaders, minimum 900 fastballs, this year in ride over dead zone expectation.

"Arm slot is the highest correlated thing to spin direction," Willard said. "Spin direction is the highest correlated thing to Magnus lift."

Toward that end, Padres starter Michael King has worked to improve his vert by slightly shifting his release. He is a lower-slot righty with a crossfire delivery and more proclivity for horizontal movement than vertical ride. However, since 2022, his four-seam fastball has been a significant part of his repertoire, and this year, the average induced vertical break on that pitch rose from 15 inches to 17 inches. That has resulted in increased separation -- more deception -- between his four-seamer and his sinker.

"My axis is still never going to be right at 12 o'clock," King said. "But if my sinker's at that 2:15 or 2:30 mark, if I can get that four-seamer to be closer to a 1 o'clock axis, that's where I can get to 17s and above."

Less than a decade ago, virtually no one in baseball spoke in such terms. Now, King revels in the fact that his home stadium, Petco Park, recently began displaying the vertical and horizontal movement of every pitch on ribbon boards behind home plate.

That's how far induced vertical break has come. In a little more than a decade, it's gone from a stack of papers on a steakhouse table in West Virginia to the LED displays of multiple Major League stadiums. Induced vertical break -- once you know where and how to find it -- tells the story of modern pitch design, even as teams continue striving for the next frontier, whatever it might be.

"Mathematically, there is an actual theorem out there saying you can never know everything there is to know about math," Kalk said. "And if you can't know everything there is to know about math, then you can't know everything there is to know about everything that is built off math."

Pitching, it turns out, is one of those things.

"So," Kalk said, "there will always be more to discover."

The 'rising fastball' was a tantalizing myth. Then teams started teaching Induced Vertical Break