Driveline Trained, Janson Junk Is Pounding the Strike Zone in Miami

Janson Junk is making the most of his opportunity in Miami. Inked to a minor league contract by the Marlins in February, the 29-year-old right-hander joined the big league club in late May and has since gone 6-2 with a 4.04 ERA and a 3.08 FIP over 82 1/3 innings. And while his 17.5% strikeout rate is rather pedestrian, it is accompanied by a 2.7% walk rate — the lowest among major league hurlers who have tossed at least 60 frames. Indeed, pounding the zone has become Junk’s M.O.

Not bad for someone whose track record is that of a well-traveled pitcher who’d done little to impress at baseball’s highest level. Prior to being signed off the scrap heap by the Marlins, Junk had logged a 6.75 ERA over 40 innings while toeing the rubber for the Los Angeles Angels, Milwaukee Brewers, and Oakland Athletics across the 2021-2024 seasons. Before then, he spent parts of five years and four seasons (because there was no minor league baseball in 2020) in the Yankees’ system. New York selected him out of the University of Seattle (where his teammates included Tarik Skubal) in the 22nd round of the 2017 draft.

Junk entered my radar in 2021 when he was pitching with the Yankees’ Double-A affiliate, the Somerset Patriots. That summer, Junk appeared as guest, along with big league veteran Clayton Richard, in a pitching-nerd episode of FanGraphs Audio. With that conversation in mind, I made it a point to catch up with Junk when the Marlins visited Fenway Park last weekend.

I began by asking Junk a question that has led to interesting conversations with other hurlers when we’ve talked later in seasons: What is the worst pitch you’ve thrown this year?

“It was earlier in the season — I don’t recall the team or batter — but it was one I didn’t execute,” Junk replied. “I throw the spike changeup now, and my finger flattened out a little bit. I got behind it way too much, and the pitch was warped. It was like [positive] 10 vert, eight horizontal. It was very mediocre movement and it got ripped.”

Junk clarified that the “spike changeup” he was referring to is the increasingly popular kick change, and while the recent addition to his arsenal has been a net positive, he has thrown other clunkers as well. Fortunately for him, he’s also gotten away with some of those mistakes.

“I threw another bad one against Houston, two starts ago,” recalled Junk. “I gave up a two-out double, then they scored on another double, so it was like, ‘OK, let’s not let the game get out of hand.’ I called the catcher out. We talked, and I was like, ‘I really like changeup here.’” He decided to keep throwing the changeup even after those rough offerings because overall, “I had been throwing some good ones.”

“I threw a first-pitch changeup [to Jesús Sánchez],” he continued. “I saw it going to the plate looking straight as an arrow, and thank god, we got a rollover on it. I turned around — in Miami they have the metrics on the scoreboard — and it was like a 10-and-eight BP fastball. I think it was just the velo [difference] that threw him off.”

The point of the worst-pitch-you’ve-thrown question is not to be overly negative; rather, it serves as a way into a broader discussion of a pitcher’s repertoire. As was the case here, in talking about a particularly awful pitch and why it was bad, we can compare it to the typical attributes of that pitch type and understand how and why it usually works.

“The kick change is new to me this year,” the Seattle-area native said. “I tried a splitter for two years, but wasn’t able to get the consistency that I wanted out of it. I needed to figure something out. When I went back to Driveline this past offseason, my throwing trainer was like, ‘Why don’t you try a kick change?’ I had been trying to throw a more classic changeup, kind of like Skubal’s changeup — like everybody else around the league who is similar with a higher arm slot — but it was getting too runny-lifty. I wasn’t killing vert. I’ve always been a high vertical break guy — my fastball is high vert — and it’s always been a struggle for me to kill vert.

“Adding the kick to it, I was able to change the axis of the ball at release and be able to create that tilt to make it go five vert and below,” continued Junk. “Before, if I threw a 10 vert, I was like, ‘Oh, thank god,’ Now if I throw a 10, I’m like, ‘Ugh. That’s a little high.’ The kick change is pretty easy for me because I supinate the ball, and through the supination I’m able to get that kick going. I kind of cut it, and then the kick sinks it. It looks like it’s cutting, and then it goes down. It’s like this weird seam-shift.”

One of his breaking balls has also undergone a revamping. Junk went into the year spiking his sweeper — being more middle-finger dominant helped him shift the axis down — but a month and half ago, he went back to the two-seam-grip sweeper he’d thrown in years past. Marlins pitching coach Daniel Moskos, with whom he’d worked in the Yankees system, made the suggestion. Junk proceeded to try the old grip in a bullpen session, and the result was a higher-velocity pitch that not only has become more horizontal, but also has gotten more lift. As Junk put it, “The model likes it, so we’ve brought back that little whirlybird two-seam sweeper.”

Which brings us to the plus-plus command that he has been displaying in his breakthrough season. He’s worked on optimizing the nastiness of his stuff for a while now — hence his training at Driveline — but what about his minuscule walk rate? Those two attributes aren’t always simpatico. How is he melding them?

“I think the biggest thing is that I worked heavily on [Driveline’s] Intended Zones [Tracker],” the righty replied. “This was in the offseason, before I got picked up by the Marlins. When I went to the bullpen last year my walk rate went up a little bit, and I hate walking people, so that was a big emphasis. Every single time we would hit a mound, and there wasn’t a catcher there, we would go to the Intended Zone. We’d get feedback, see what our misses were like, and work on how to correct them.”

As an organization, Moskos said, the Marlins preach throwing lots of strikes and prioritize pitchers who pound the zone. That’s what made Junk such a good fit for them.

“The most simple way to [describe our approach] is, ‘Throw nasty strikes,’” the pitching coach told me. “You’ve probably heard something similar in verbiage from other places — some version of ‘throw strikes hard’ — but essentially we want to create robust arsenals, the best pitch shapes and velocities possible, and be middle of the zone pre-two [strikes] and out of the zone with two [strikes].”

Unlike some of his teammates, Junk doesn’t have an overpowering arsenal. With a fastball that averages 93.6 mph — he topped out at 96.6 mph the day after we spoke — he lacks the explosiveness of a Eury Pérez, Sandy Alcantara, or Edward Cabrera. That isn’t to say he is without quality offerings, though. He makes up for his 37th-percentile velocity with strong secondaries and command, as well as confidence, competitiveness, and an aggressive approach.

“I’m out there throwing with controlled aggression. It’s about confidence, about trusting and understanding my pitch movements. It’s about knowing that I can get these guys out.”