When the amateur baseball season started in early 2012, Lucas Giolito was one of the favorites to be drafted first overall. No high school right-handed pitcher had ever been drafted first overall before, but Giolito, a 6-foot-6 righty out of Harvard-Westlake School in Los Angeles, was something special. In addition to elite size, Giolito combined an explosive upper-90s fastball with an exceptional curveball, a promising changeup, and unusual polish for a teenager.

Seven years later, Giolito, now 24 years old, is carving up the American League. He’s fourth among pitchers in the AL in bWAR and Baseball Prospectus’s WARP, trailing only Justin Verlander, Chris Sale, and Charlie Morton in the latter. Giolito is third in the AL in ERA, eighth in K/9 ratio, and second to Verlander in hits allowed per nine innings. These are the makings of an All-Star season and perhaps even a serious challenge for the Cy Young, and could establish Giolito’s place as one of the most promising young pitchers in baseball.

Going from historic draft prospect to top-end big league pitcher looks like a pretty straightforward career trajectory. But Giolito’s path to the top of the statistical leaderboards was as circuitous as a Family Circus map of Billy’s travels, as broken as Rascal Flatts’s titular road.

Draft prospects come on a sliding scale of risk and reward. Generally speaking, pitchers are riskier than hitters because of the chance of catastrophic injury, and high school pitchers are riskier than college players because of the extended developmental curve. Being left-handed helps, as lefties who throw at or close to 100 miles per hour are so rare they sometimes present enough upside as to be irresistible.

Since the draft was instituted in 1965, three left-handed high school pitchers have gone no. 1 overall. Only one of them, David Clyde, so much as threw a pitch in the majors. Brien Taylor, the top pick in 1991, is one of the most famous draft busts in baseball history, and the top pick in 2014, Brady Aiken, has faced just nine batters in the past two seasons, three of whom scored. It’s likely that when Aiken’s career is over, two of the three high school pitchers drafted first overall will end up as two of the four no. 1 overall picks never to play in the majors.

Giolito, because of his size, tools, and maturity, had very few red flags for a high school pitching prospect. But that qualifier—“for a high school pitching prospect”—all but negates the first half of that sentence. In March of his senior year of high school, he hurt his elbow and didn’t pitch again all season. High school pitchers are risky to start, but an injured high school pitcher is another proposition altogether. In a class that included talented high school hitters like Carlos Correa, Byron Buxton, and Corey Seager, as well as safer-seeming college players like Florida’s Mike Zunino and LSU’s Kevin Gausman, Giolito started to drop.

His bonus demands didn’t help. The 2012 draft was the first year of MLB’s current bonus pool system, which restricted teams’ ability to pay draftees. Giolito had expected a top pick’s bonus, or something like it; Correa, the no. 1 pick, took an under-slot deal for $4.8 million, while Buxton got a $6 million bonus, the highest in the class. Coming from a Hollywood family (his parents are actors, and his uncle Mark Frost cocreated Twin Peaks), Giolito had the luxury of turning down an immediate bonus for a bigger payday later. He committed to UCLA—which had the year before put two pitchers, Gerrit Cole and Trevor Bauer, in the top three picks in the draft—and Giolito seemed likely to follow through on that commitment. Cole had turned down a seven-figure offer from the Yankees out of high school, and three years later emerged as the no. 1 overall pick with an $8 million signing bonus that remains the highest in MLB draft history. Giolito could have done the same.

Giolito fell all the way to Washington at no. 16, and ultimately signed for a hair under $3 million. He wasn’t even the highest-drafted pitcher from Harvard-Westlake that year, as lefty Max Fried went to the Padres at no. 7 overall. (Cardinals right-hander Jack Flaherty was a sophomore that year, giving Harvard-Westlake what is probably the best pitching staff in the history of high school baseball.) Shortly after he turned pro, Giolito underwent Tommy John surgery, but when he returned in 2013, he touched off a four-season run of minor league dominance. Baseball America, Baseball Prospectus, and MLB.com all rated him a top-10 overall prospect in both 2015 and 2016.

But just as Giolito looked poised to dominate the majors, everything started to fall apart.

Giolito got his first taste of big league action with the Nationals in 2016, with four scoreless innings in his MLB debut on June 28. But his first cup of coffee quickly went sour. In six appearances, Giolito allowed 18 runs in 21 1/3 innings, and walked more batters than he struck out. This wasn’t that big a deal—Giolito was still only 21, and had perhaps been thrown into the deep end of the pool before he was ready. His stock was still high enough for the Nationals to make him the centerpiece of the blockbuster Adam Eaton trade the following offseason, and the best of a truly dizzying collection of hard-throwing youngsters around whom the White Sox intended to rebuild.

Giolito returned to the minors to start 2017 and pitched well enough in seven late-season big league starts (2.38 ERA, with opponents hitting just .190/.258/.387 against him) to earn a full-time rotation slot going forward.

The one troubling thing about Giolito’s 2017 season was his lack of strikeouts. Whatever else Giolito had been as a prospect, he was a power pitcher with a knockout fastball and a devastating curve. But in 2017, Giolito’s average fastball velocity had dropped to 92.8 miles per hour, down from 94.2 the year before, and 96 or higher early in his minor league career. His K/9 ratio was 6.75, 151st out of the 207 starting pitchers who threw at least 40 innings that year, one place above Jason Vargas, and four places above Matt Harvey, whose arm was coming off his body at that point in time. As a result, both FIP and DRA estimated that Giolito had outpitched his peripherals by as much as two runs per nine innings.

Even this was a small enough sample to be explained away; Giolito appeared in the majors after throwing more innings than he ever had in his life, after all. But in 2018, Giolito got 32 starts in the majors, in which he regressed all the way back to the mean, and then some.

In his age-23 season, Giolito appeared atop the MLB leaderboards for the first time, but not in the categories one might have predicted back in 2012. His underwhelming strikeout rate dipped slightly, but his walk rate nearly doubled, from 6.7 percent to 11.6 percent. His 90 walks led the American League, and his 118 earned runs allowed led all of Major League Baseball. It’s not just that he was bad enough to post a 6.13 ERA, it’s that the White Sox were so hard-up for pitching last year they let him throw 173 1/3 innings, allowing him to give up that staggering number of earned runs.

Baseball-Reference rated Giolito as being 2.8 wins below average and 1.3 wins below replacement. Baseball Prospectus had Giolito at minus-2.5 WARP, making him the second-worst pitcher in baseball by that measure.

By the end of 2018, it had been two full seasons since Giolito was a top prospect. In those two years, Giolito’s velocity fell off and his ability to miss bats evaporated, and MLB hitters were crushing him so badly he was one more bad season from being legally required to change his name to Jennifer Paige.

Obviously Giolito had to change something, or else he’d stop getting a top pitching prospect’s chances and start being treated like a guy with a career ERA of 5.48 and an unsustainably low strikeout rate. Giolito’s success is the result of a variety of mechanical, mental, and training tweaks that read like a greatest hits version of contemporary pitching success stories.

In late February, just as spring training was heating up, he explained to James Fegan of The Athletic exactly what he’d done over the offseason. Giolito had spent the 2018 season constantly tinkering with his mechanics and pitch mix, and struggled to find something that worked consistently. So he ended up working with weighted balls to refine a new delivery, and studied high-speed film of himself using a Rapsodo camera.

Weighted ball programs and Rapsodo might ring a bell because they’re the hot equipment in baseball player development right now, notably favored by Bauer and Driveline Baseball, as well as coaching staffs across the league.

“I don’t do a full-on Driveline program, I call it my personal warmup that I tailor for myself,” Giolito told Fegan. “Naturally from doing that, early in the offseason my arm action started to shorten up. It went from stab out, behind my back, long, bring it back up to a more compact just out of the glove, up and fire. The results have been great. It feels better, I feel healthier. It’s a more clean action.”

Here’s Giolito last year.

For a pitcher with such long arms as Giolito’s, that stabbing action added complexity to the delivery, which made it hard to find a consistent arm slot and repeat his motion well enough to command his pitches. It also exposes the baseball to the hitter extremely early in the windup, which made the ball very easy to track coming out of his hand.

In 2019, Giolito is keeping his elbow bent and the baseball tucked in behind his torso, which in addition to feeling more natural for him, hides the ball from hitters until later in the delivery.

After sitting below 93 miles an hour for the past two years, Giolito’s four-seamer is once again coming in at 94.6 miles per hour, with about an inch and a half more of perceived rise.

He’s also made a familiar change to his pitch mix. There’s an obvious precedent for a big-bodied, hard-throwing right-hander out of Southern California who entered pro baseball with a hard fastball plus a breaking ball and good feel for a changeup, but delivered curiously low strikeout numbers in the big leagues: Cole.

In 2018, Cole junked his two-seam fastball and concentrated on throwing his four-seamer. A two-seamer or sinker trades velocity for downward action designed to get batters to swing over the top of the pitch and hit it on the ground. But in the time of uppercuts and the swing-plane revolution, that downward action actually keeps the baseball in the batter’s upward swing path and makes it far easier to square up. A four-seamer, which stays up in the zone, is actually better for inducing batters to swing and miss, or to pop the ball up.

When Cole went exclusive with his four-seamer, he had his best season in three years, and after struggling to miss bats at times with Pittsburgh, he led MLB in K/9 ratio in his first season with the Astros. This year, he’s striking out 13.8 batters per nine innings, which would be an all-time record for a starting pitcher if he keeps up that rate over 162 innings or more.

In 2018, Giolito threw his sinker about 20 percent of the time, and it was his most-used fastball in 10 of his 32 starts. He hasn’t thrown it once this year and has de-emphasized his curveball, instead relying more on his four-seam fastball and changeup.

When Giolito explained all this, back in February, it wasn’t a sure thing these adjustments would stick, much less work. Indeed, he got knocked around in April, allowing a total of 13 runs and nine walks in his first three starts, then tweaked his hamstring in his fourth start and ended up on the IL.

Giolito allowed three runs in five innings in his first start back, May 2, though he struck out seven. Since then, he’s been unhittable: In his past seven starts, all of them wins, Giolito has struck out 59 batters and walked just 10 in 51 1/3 innings. He’s allowed just 25 hits and one home run, and just five runs overall, for an opponent batting line of .145/.200/.185, and an ERA of 0.88.

He’s also developed a good rapport with catcher James McCann, who came over to the White Sox this past offseason after five years with Detroit. Giolito credits McCann with doing most of the in-game thinking, which allows Giolito to work faster and with a clearer mind than in years past. That adjustment to the in-game mindset is reminiscent of another gigantic right-hander from Southern California, Tyler Glasnow, who was enjoying a breakout season of his own before a forearm strain put him on the IL in early May.

Even taking into account that bad first month, Giolito has been an entirely different pitcher in 2019.

Considering how far into the season the White Sox are, Giolito is on pace to make about 30 starts this year, and to throw somewhere between 180 and 190 innings if he stays healthy. That innings load would be comparable to the innings total (180 2/3) that 2018 AL Cy Young winner Blake Snell put up last year, and Giolito’s current rate stats (2.28 ERA, 5.6 H/9, 10.7 K/9, 2.13 DRA) are comparable to Snell’s in 2018 (1.89 ERA, 5.6 H/9, 11.0 K/9, 2.44 DRA).

If Giolito just keeps up his current pace, he’ll establish himself as one of the best pitchers in baseball, and deliver on the promise he showed as a high school senior. It only took seven years, a Tommy John surgery, a trade, multiple mechanical tweaks, multiple changes to his pitch mix, and some new training tools. Just like everyone expected.

Michael Baumann