Like race car drivers and opera singers, pitchers need to summon another gear in pivotal moments. It is how Jack Flaherty in 2019, at just 23 years old, joined Clayton Kershaw and Roger Clemens as the youngest pitchers in the past 48 years with a league-leading WHIP under 1.00. Averaging 93.8 mph with his heater, Flaherty, then with the St. Louis Cardinals, could hit 97 when he floored it.

The complement of two sharp breaking balls also made him the best young pitcher in the game. Riches and awards were to follow as surely as they did for Kershaw and Clemens.

His ascension never happened. The pandemic and injuries, especially to his oblique and shoulder, cast him into such a four-year wilderness of mediocrity (4.42 ERA) that when he hit free agency last winter at the prime age of 28, he could do no better than a one-year, $14 million prove-it flier with the Detroit Tigers.

That contract today looks like one of the best bargains of the winter. Jack is back. Entering a start Monday against the Cleveland Guardians, Flaherty leads the league in strikeouts, has posted a historic strikeout-to-walk rate to start a season, has tweaked his delivery and pitch usage and, yes, has rediscovered that extra oomph when he steps on the gas.

Look no further than the 1-and-2 fastball he threw to Lars Nootbar of the Cardinals in his last start Tuesday. Dotting the outside corner, the pitch was clocked at 97.8 miles per hour, as hard as Flaherty has thrown a baseball in five years.

“There were definitely times last year where I wanted to go to another gear and it was like it just stayed the same,” Flaherty says in a conversation I had with him earlier this year. “It was weird, and it just wasn't there, for whatever reason. And this year when I want to go to another gear, I’ve been able to get there.”

Says Tigers manager A.J. Hinch, “He was electric in his last start. He can really miss bats with his two breaking balls. His fastball was special the other day.”

Flaherty tied an American League record by striking out the first seven batters he faced in that game against his former team. He tied a career high and an MLB season high with 14 strikeouts overall. His average fastball velocity was 95.1, the fourth highest game average of his career and his best in four years. He obtained 24 swinging strikes, one short of his career high set in 2018. Ten of those whiffs came on his fastball, tying a career high.

The rebuilding of Flaherty began as a free agent after last season, which included  telephone conversations with Tigers pitching coach Chris Fetter and assistant pitching coaches Robin Lund and Juan Nieves. They noticed his fastball properties improved after his Aug. 1 trade to the Baltimore Orioles, though his ERA in nine games with Baltimore was 6.75.

“I didn't feel great and by the end, it was just, ‘How can I get outs?’ “ Flaherty says. “Regardless of how it feels and whatnot, it's September. You’re put into a pennant chase. It was, ‘We'll just see. Find a way.’”

The Tigers’ coaches had success that year rebuilding another free agent pitcher, Michael Lorenzen, then 31. They de-emphasized his sinker in favor of more high-spin four-seamers. Lorenzen set career highs in wins, innings and strikeouts, made his first All-Star team and, after a trade to Philadelphia, threw a no-hitter. They had plans for Flaherty, but only hinted at them during the recruitment.

“When things were getting serious, we were on a call for two hours,” Flaherty says. “We talked this out. They presented ideas, but they don't want to … Those are tricky calls. They can't give you everything, like, ‘Here's all the secrets of what we think is going to make you better.’  But like, ‘You know, here's what we saw last year, and we can kind of help you get back.’  I've definitely never gone through it.

“Those calls are tricky because it's like, how do you ask them, ‘What can you do to help me?’ And then they give you a little bit, but not be able to give you everything because ‘If you don't sign here, we don't want to tell you this is what to do.’

“But in the end, it was their effort and the attention to detail that sold me.”

Flaherty signed with Detroit on Dec. 20. Two weeks later, Frankie Montas, who is three years older than Flaherty and threw just 1 1/3 innings last season, signed with the Cincinnati Reds for $16 million, $2 million above Flaherty’s salary.

“Obviously it was a different offseason,” says Flaherty, who was a free agent for the first time. “At first it was not like having a team or anybody to go to and say, ‘Hey, what adjustments need to be made?’ So, I was kind of diving into it with my own team, my group, and figuring out, ‘What do we need to change?’ Because obviously, I was healthy, great, but I was not able to sustain success the way I wanted to. I didn't feel like the ball came out the same way. So, we had to dive into that and start making those adjustments.

“Once we signed here, then it was constant conversation [with the Detroit coaches]. ‘Okay, these are the adjustments that we think we can make.’ Now I had somebody to bounce ideas off of and go back and forth and send video to when it came time for a [bullpen]. So, it was a little bit more of, I kind of had to get back to a daily grind. Every day. And try to get back to the way I wanted my body to feel.”

Flaherty did not overhaul his delivery. He still has the smooth, old-school, three-part windup – hands over the head, kick and fire. He worked at fine-tuning the tempo and sequencing of that delivery. Ever since he starred on the mound and at shortstop for Harvard-Westlake High in California, Flaherty has been at his best when he relies on athleticism more so than pure mechanics. The injuries had compromised that athleticism.

“There were points last year where I just didn't … I tried as hard as I could to just be an athlete and for whatever reason it just felt weird,” he says. “I would say that I'm moving a lot better this year. Whether you want to call that mechanical? Sure. But I think the way that I'm going to fix it is the way I've moved, the stuff that works better for me. We really dove into the way that I was moving last year, and it would just be like, ‘Yeah, that's it!’”

An even bigger change came with how Flaherty used his pitches. Back in 2019, Flaherty threw fastballs 58.4% of the time. Since then, as analytics grew more sophisticated and technology around the game exploded, fastball use in MLB has declined every year—down to 46.7% this season, an all-time low. 

The change was driven by a new generation of coaches, such as Fetter, who grew up with those modern tools. They know average spin is harder to hit than above-average velocity, and that the shape of spin can be custom designed. Fetter, 38, was hired by the Tigers after the 2020 season after serving as pitching coach for the University of Michigan. In a reversal of the historical paradigm, change flowed up to the majors from amateur baseball, including colleges and private instruction facilities.

Under Fetter, the Tigers have reduced their fastball use for a fourth straight year, ranking among the bottom 11 teams. Despite finding his turbo-boosted fastball again, Flaherty is throwing about as many fastballs as he did last year (43.7%), which is below major league average.

The biggest changes Flaherty has made under Fetter are ditching his ineffective cutter (.545 slugging percentage last year) and leaning much more on his swing-and-miss slider and curveball. He is throwing a career-high 52.6% breaking pitches, up from 44% last year and the fourth-most in MLB (min. 500 pitches). He has cut the batting average against his slider from .339 to .224 and his curveball has the third-most horizontal movement in MLB (min. 100 curves).

Pitchers who trade fastballs for spin often do so at the cost of more walks. Not Flaherty. He became only the seventh pitcher with 50 strikeouts and no more than five walks through the month of April. Even allowing that the modern era features more games in April, he joined a very impressive group:

Sure, it’s only six starts. And Flaherty hasn’t thrown 150 innings in a season since his breakout year of 2019. But one month into this season, the baseball is jumping out of Flaherty’s hand again. The athletic feel in his delivery has returned. So has 97 when he steps on the gas. It took an entire winter, when a 28-year-old free agent starter could do no better than a one-year deal, to bring back Jack.

“There’s working hard,” he says about his way back, “and then there's also being super intentional about it.”