Tigers Prospect Jimmy Kerr Talks Hitting

Jimmy Kerr is pretty low-profile as far as prospects go. The 24-year-old infielder was a 33rd-round senior-sign in 2019 and currently playing for the Detroit Tigers’ High-A affiliate, the West Michigan Whitecaps. A standout during the College World Series in his draft year, he remains relatively unknown beyond the University of Michigan, where he earned a degree in Industrial Operations Engineering.

His knowledge of hitting promises to increase his profile. Kerr faces long odds to reach the big leagues, but he’s already begun gaining a foothold as an instructor. Last year, he co-founded K2 Baseball, an elite training facility in Ann Arbor, Michigan.

Kerr talked hitting prior to a Whitecaps game earlier this month.


David Laurila: Let’s start with your training facility. How did that come about?

Jimmy Kerr: “It was over the pandemic. A couple of my college teammates and I were up in northern Michigan — my parents have a place in Walloon Lake — kind of escaping for the summertime. We were working out at the local high school, trying to stay in shape, and had also ordered some workout equipment. Everybody was trying to start their own home gym at that time, so it was backordered and took awhile [to arrive].

“Once the weather turned and guys were going back to school, we rented out a space in Ann Arbor and put all the workout equipment in there. We put in a batting cage, turf, a portable mound, and started running a little baseball facility. It started with just some of our Michigan teammates who are in pro ball now, and then we turned into a business where we’ve got high school kids and youth baseball players. We’re doing training programs, lessons, and all that.”

Laurila: Who else was involved?

Kerr:Ben Keizer and I started it together. We had Jeff Criswell, Jack Weisenburger, Jordan Nwogu, and Jack Blomgren working out there. Most guys go back after their junior year to take classes, and we weren’t allowed in the Michigan facilities because of COVID, so it was the perfect spot for us to work out and get ready for spring training.”

Laurila: I assume you’ve incorporated tech at your facility?

Kerr: “Yes. I had been using a Blast sensor for awhile, and I think it’s one of the best tools for hitters to break down their swings. We used one with all the guys in there. And Rapsodo had a deal for minor leaguers over COVID, so we got a pretty good discount on a Rapsodo. We also have a little pocket radar. The University of Michigan helped us out a lot with some of the equipment; they kind of just loaned it to us, so we use all of that good stuff.”

Laurila: Do a lot of the kids who train at your place embrace the tech?

Kerr: “They do. It’s been really new for most of the kids who have come in, so they didn’t really know they wanted to train with it until they saw how great the information it is. Now we’ve got a lot of guys coming back [and] saying ‘Can we use the Blast sensor today?’ It’s really easy to explain to them what’s going on in their swing by just looking at the Blast sensor. And then it’s really easy to show them improvement from one swing to the next, throughout their training process.”

Laurila: What have you learned about your own swing?

Kerr: “That’s a good question. One of the biggest metrics on there is called rotational acceleration. It’s kind of how your body creates energy, and that metric shows if you’re doing a good job of firing your hips first, shoulders first, arms and hands. I noticed my swing was different from tee to flips and from flips to BP. I wanted to break down why it was so different.

“Some guys have a tendency to get into bad habits on tee swings, which is what I was doing. My rotation acceleration was terrible on tee swings because I would get kind of lazy and over-rotate my shoulders. That’s because you don’t have to be on time for anything. I want to try to keep my swing as good as it is during BP, because that’s where I got my best numbers. I want to keep my swing the same every time.

Laurila: Is that an argument against hitting off a tee?

Kerr: “I think it’s more of an argument for the Blast sensor, because it can show you the discrepancies. I know that everybody doesn’t have the same problem on the tee, because a lot of kids I worked with had no issues. They had the same swing, tee, flips, no matter what.”

Laurila: Do you find value in BP, or do mostly like to hit off machines that can approximate in-game velocity and movement?

Kerr: “That’s a good question, too. I think all of them are important. But a lot of people really like seeing the live arm to help with their timing. Machines are hard to time because of how they’re fed, how they shoot the ball out, and where they go. It’s not as easy to try to predict where the pitch is going to be, so I feel like if I’m able to barrel balls consistently off the machine, then I’m ready to go for a game.

“But I do like hitting on the field. I like to see the ball flight. Of course, even in a cage you can get a pretty good visual, especially from a spin perspective. Something I like to focus on is getting good backspin to all parts of the field, and not flaring balls off, or hooking balls pull-side. With HitTrax you can be in a cage and kind of have the same thing you get on the field.”

Laurila: Hitting on the field, do you ever find yourself wondering what the metrics are?

Kerr: “Yes. And I don’t know if you were here when he hit BP, but we actually put the TrackMan numbers up on the screen. We had the exit velocity, the launch angle, and the spin rate. You don’t want super-high spin coming off the bat. You want kind of low, because that means you squared up the ball a little bit.”

Laurila: When you look at those types of numbers, do they usually match up with what you felt?

Kerr: “Yeah. It’s something Chris Fetter would say. He was our pitching coach at Michigan — he’s obviously [with the Tigers] now — and he’d say that it’s important to put a number to the feeling. We feel what we feel, but being able to constantly put a number to that sharpens what you feel even more.”

Laurila: How much have you changed as a hitter? If I looked at film of you as a senior at Michigan and compared it to now, would I see the same guy?

Kerr: “It would be similar. I think that goes for a lot of guys. Guys make little adjustments, but it’s surprising how similar the swings look from early on in a career to the end.”

Laurila: What about when it comes to the “launch angle” swing that so may hitters have tried to adopt in recent seasons?

Kerr: “My junior year to senior year of college, I started hitting for a lot more power. A lot of it came from gaining weight and getting stronger, but a lot of it came from hitting more fly balls. But I never changed my swing to try to get better launch angle or to hit more fly balls. The only thing I changed was my target on the ball. It’s different for different guys, but my whole thing had always been to stay through the middle of the ball, and I started visualizing down through the top of the ball. That actually helped me get backspin and lift the ball a little better.

“Guys have had different ways of creating launch angle, and it’s not always just changing how you swing the bat. It’s so hard to be on plane with the ball. That’s another huge Blast metric I talked to guys about when they came in [to the training facility]: their attack angle. You want it to match the pitch as well as possible. I don’t think guys are really trying to swing up at the ball, it’s more of what part of the ball you’re trying to hit.”

Laurila: One hitter I’ve talked to said that he used to try to hit line drives over the pitcher’s head, and now he tries to hit line drives over the centerfielder’s head. It’s more about approach than the actual swing.

Kerr: “It’s almost all mental. A lot of guys pick targets on the field, where they want to go. I’ve heard that Albert Pujols’ two-strike is approach is to try to hit the fastball down the oppo line. Maybe in a 3–1 count you’re trying to hit the top left corner of the batter’s eye, to stay inside the ball and get good launch on it. Hunter Pence would do batting practice on right-on-right sliders and try to hit pop-ups to the first base dugout. He would try to stay inside and under it so much, because he knew that’s how they were trying to beat him. By trying to hit pop-ups to the first base dugout, he would end up hitting lasers. Hitters use didn’t visuals, different mental cues, to create different outcomes.”

Laurila: What about the swing itself? While not all hitters are the same, there are certain things you need to do to be successful. Is that correct?

Kerr: “There are definitely parts of guys’ swings that are really important. You can break down 99% of professional baseball players and have five really similar things about their swings. Keying on those is huge. But you also don’t want to take away the natural feeling of swinging a bat.”

Laurila: What are the five things you were referring to?

Kerr: “We broke them down in college — five things we looked at — and hopefully I can get all of them. One is your gather. When you load, you want to make sure you have almost all of your weight on your back leg. You want good downward attack angle with your shoulders. When the front foot hits — toe touch — you want stacked torso, shoulders over hips, positive attack angle with the shoulders. Some people look for barrel above head. And then at heels strike — when the heel hits — you want to be starting to rotate, but with the hands staying back as you’re creating tension in your core. Hips go, shoulders stay. Then, at contact, eyes behind barrel. You want to make sure you stay extended through the ball, straight arms, eyes down the barrel, barrel at the pitcher.”


Earlier “Talks Hitting” interviews can found through these links: Jeff Albert, Greg Allen, Nolan Arenado, Aaron Bates, Bo Bichette, Cavan Biggio, JJ Bleday, Jay Bruce, Matt Chapman, Michael Chavis, Jacob Cruz, Nelson Cruz, Paul DeJong, Rick Eckstein, Drew Ferguson, Justin Foscue, Joey Gallo, Devlin Granberg, Andy Haines, Mitch Haniger, Tim Hyers, Trevor Larnach, Evan Longoria, Michael Lorenzen, Gavin Lux, Dave Magadan, Trey Mancini, Edgar Martinez, Don Mattingly, Cedric Mullins, Daniel Murphy, Drew Saylor, Fernando Tatis Jr., Justin Turner, Mark Trumbo, Zac Veen, Luke Voit, Jordan Westburg, Jesse Winker, Nick Yorke.

David Laurila grew up in Michigan's Upper Peninsula and now writes about baseball from his home in Cambridge, Mass. He authored the Prospectus Q&A series at Baseball Prospectus from December 2006-May 2011 before being claimed off waivers by FanGraphs. He can be followed on Twitter @DavidLaurilaQA.

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2 years ago

Great interview! It’s clear that he’s got a good head on his shoulders, and you can’t help but cheer for him to make the bigs.