Examining Jack Flaherty's strong start to a hopeful rebound year

Jack Flaherty was one of the more interesting mid-level starting pitchers in last year’s free-agent class. The righty was arguably the best pitcher in MLB in the second half of 2019, but he didn’t cement himself as an ace in the following few seasons. He struggled in nine starts during the shortened season. Oblique and shoulder injuries cost him good chunks of the 2021 and ’22 campaigns, respectively. Flaherty stayed healthy for his walk year but allowed nearly five earned runs per nine between the Cardinals and Orioles.

That left both his camp and interested teams with questions once he hit the market. Was Flaherty still an upside play who had a realistic chance to turn in top-of-the-rotation results? If he felt that way, would he be best served taking a one-year deal and retesting the market next year? At 28, Flaherty was one of the youngest free agents of note. He ultimately chose the one-year route, signing a $14M guarantee with the Tigers that contained another $1M in performance bonuses.

It’s far too early to definitively declare the move a success, but his first month in Detroit has gone better than expected. Flaherty’s even 4.00 earned run average through 36 innings isn’t especially noteworthy. Yet he leads the American League with 50 strikeouts and has only issued five walks. His 16.4% swinging-strike percentage would easily be a career high. It’s nearly six points up from last season.

Among pitchers with 30+ innings, only Freddy Peralta has a higher strikeout rate than Flaherty’s 34%. Jared Jones is the only pitcher getting more whiffs on a per-pitch basis. Flaherty is coming off a career-high 14 strikeouts in Tuesday’s matchup against his old teammates with St. Louis.

There’s only so much a player can prove in a six-game sample, but Flaherty hasn’t missed bats at anything close to this level in five years. Using the Baseball Reference Span Finder, we see that Flaherty hadn’t recorded more than 40 strikeouts in a six-game stretch at any point since his dazzling finish in 2019. While the ERA hasn’t caught up, Flaherty is dominating the strike zone in a way that he hasn’t for some time.

Flaherty’s stuff has ticked up slightly in the early going. His fastball is averaging 93.8 mph, around half a mile per hour above where it sat in the previous two seasons. Perhaps more impactful has been the increased effectiveness of his breaking stuff. Flaherty’s best pitch, his slider, is missing bats at a high level after it waned in 2022-23. Opponents have come up empty half the time they’ve offered at his curveball. Flaherty is attacking hitters, particularly left-handers, with the breaking pitches a little more frequently than he has in previous seasons.

There’s a long way to go before he puts the questions about his 2021-23 performance behind him completely. As the season progresses, he’ll face tougher opposition than he has gotten thus far. Of his six starts, four have come against teams (the White Sox, A’s, Rays and Cardinals) that have been subpar offensively. Only his two starts against the Twins have been against a club with an above-average team batting line. While the Twins have been solid overall, they’re a high-strikeout offense.

Yet if Flaherty stays healthy and continues to overpower opponents at anything close to this level, he’ll be in line for a much more lucrative free-agent trip. He’ll play all of next season at 29, which is still atypically young for a free-agent starter. He’d be a clear qualifying offer candidate (assuming the Tigers stay in the postseason mix and don’t trade him at the deadline), but he shouldn’t have much issue turning that down and landing a better multiyear pact.

Next winter’s class has a lot of high-variance but intriguing starters who could dramatically improve their stock in the next five months (i.e. Luis Severino, Walker Buehler, Frankie Montas, Blake Snell). Flaherty has a legitimate path to the top of that group, which could make him the No. 3 pitcher available behind Corbin Burnes and Max Fried.