Lookout Landing, a Seattle Mariners community

By flygutifly on Jul 1, 2022, 8:03am PDT +

Hello and welcome back to FanPost Friday! With the Mariners dealing with suspensions and injuries currently, it seems possible that we might be seeing Jarred Kelenic's return to the big leagues in the near future. Luckily, poster flygutifly has provided us with another banger of a FanPost featuring a deep dive analysis into Kelenic's current batting performance in the minors. Enjoy! - Eric

I am so excited for Jarred Kelenic to blossom into an impact bat for the Mariners. However, when I saw this tweet, I felt a moment of fear that he was truly broken:

suffice to say, writing 1400 words on Kelenic's hit tool didn't leave me with much confidence things were trending in the right direction, no matter how much he crushes Triple-A fastballs (and he is doing that, again) @baseballpro https://t.co/dfhlmQE2pD pic.twitter.com/pnkXLvDcgh

The author is treating Kelenic’s performance up to that point as a monolith, but I want to know if he is making improvements. Development is not linear of course, but are his whiff problems getting worse or better? Is he even seeing many breaking balls in AAA?

It seems that something about Kelenic’s offseason swing adjustments affected his ability to identify and lay off sliders and change ups. In 2021 he saw 270 sliders and whiffed a perfectly acceptable 36.3%. In 2022 he has seen 80 MLB sliders and whiffed on an eye watering 60.7%. On 59 changeups, he has whiffed 51.6% of the time compared to 42.4% last year. To put things in slightly bigger buckets:

Of course, we are living in the land of small sample sizes and none of this should be used in a predictive sense. This is purely to get an idea on what Jarred needs to fix before he comes back up to MLB.

I am no swing mechanics expert, but I will link a clip below from a double in April and then a double last week in Tacoma. It is a little difficult with the different camera angles, but what I am seeing is a slightly more open stance in the second clip, a slightly higher leg kick, and less of a "windup" with his shoulders before he starts moving the bat to the ball. To my eyes - which again I am not a professional - his bat to ball looks more direct and his swing looks smoother. I went through a bunch of his early videos from this season and at least to me it looks like he was trying to get some extra power by reaching back with the bat and that was twisting his shoulders (and maybe head? Hard to tell with the different camera angles) away from the ball a little bit.

Plays like these remind me of this quote from Jarred Kelenic after his debut last year: "Ever since I was young, my dad always taught me that when you make contact, it's always a double out of the box. So that's the same mentality I've had." (sprint speed: 29.0 ft/sec) pic.twitter.com/Dg5F3PgZKg

Jarred Kelenic doubles to LF for his 2nd double of the game. pic.twitter.com/dhy6mKleAT

I am hopeful that my perceived bat to ball improvement is the first step in him making strides against breaking pitches. Before we get to the data, let me give you some context on pitch type whiff rates. There isn’t exactly some optimal number for a whiff rate for a given category of pitches. I looked at the profiles for several good to great hitters and it seems like 30-40% is where most good hitters coalesce on bendy stuff. Obviously, the pitch type whiff rate plays off overall whiff rate, as in if you are whiffing on 40% of breaking pitches you better hit the heck out of fastballs. Basically, if you are doing well everywhere else, you can support running a 40+% whiff rate against sliders and maybe even another pitch type, but 50% is probably too high. Unfortunately, baseball savant won’t let me make a leaderboard with whiff rate on pitch types, so I had to just choose some hitter profiles to look at. As I have gone through this, I have been using 40% as a target threshold. Just to throw an example out there, Mike Trout is whiffing on 38% on breaking pitches, 37% on offspeed, and 27% on fastballs this year.

If you follow the Mariners minor league teams, you know that offense numbers coming out of Tacoma are a little inflated. On the surface, Jarred’s performance looks amazing and almost exactly what the team needs right now. However, those results are much less important than what is under the hood: his swing decisions and bat to ball skills. That’s why I dug in to all the pitch data I could get my hands on. I went through every pitch that Jarred has seen at AAA this year.

There is no doubt in my mind that Jarred Kelenic can hit AAA fastballs. I am a strong believer in Jarred’s talent, so I am also confident that he is going to mash MLB fastballs someday too. Hitting fastballs well is a legitimate path to success in MLB if you can layoff breaking pitches out of the zone and at least get the bat on the breaking pitches in the zone, even if that is converting to fouls not hits. That’s why I think whiff rate is such an important way to measure his progress at AAA. We are lucky in the PCL to be an early adopter of the Automated Ball and Strikes System, because that means with a little URL trickery, we have access to pitch data from Tacoma.

So, I pretended to be an early sabermetrics researcher and dug into whatever I could get my hands on whenever I could get my 8-month-old down for a nap. I made an Excel spreadsheet and filled a few notebook pages with tallies going through every pitch he has seen in a Rainiers uniform. I am just a human tallying pitches up and though I was being careful, it is totally possible I made some mistakes. Basically, build some error bars into these numbers and don’t take them as exact, but we are here to do trend analysis anyway. Additionally, I put splitters in the fastball bucket, whereas I believe a lot of sources count the split finger fastball as an offspeed pitch, so probably a systemic error on my part (he didn’t see too many splitters anyway). For the sake of total clarity, my buckets are:

Fastballs – four seam, cutter, sinker, and splitter

Breaking – Curve, knuckle curve, slider

The numbers in the tables below are up to date through the 27th of June. He has played a grand total of 30 games in AAA, with 136 plate appearances, and 538 total pitches. Of those pitches 34% were breaking balls (183 total). Through Monday, he had played in 30 games, so I broke his pitch data in to 10 game chunks. Plate discipline numbers become meaningful fairly quickly, because the data set grows with every pitch. If you compare the first 10 games of data to his 2022 MLB numbers above, you can see the plate discipline numbers are very similar (with the exception of O-Contact%). I expect the numbers are at least somewhat projectable in the other direction as well, because this mostly pertains to swing choices and pitch recognition. To the best of my knowledge, having this level of granularity on plate discipline numbers from the minor leagues is unprecedented for regular folks. I have been unable to find any analysis about whether these improvements will carry over directly to MLB, but it is compelling that they were very similar as he moved down a level.

The above chart is where the good news starts. His contact percentage jumped by almost 10%. I think it’s possible he was coached to basically swing at everything close and focus on just getting the bat on the ball and it paid dividends. His swing decisions are good, shown by Z-Swing%, but his Z-Contact% is still lagging a bit behind league average. Improved contact rates with basically league average ball/strike recognition is a recipe for success for Jarred.

This brings me to the part I was most interested in: the shape of his swings and misses. I chose to use CSW% total, breaking, and offspeed, because he watched a lot of breaking balls sail past him for strikes in the early going and I wanted to capture that. As he improved his recognition though, he was able to get the bat on the ball more regularly and at least foul those pitches off. CSW% shows that more clearly.

And here is a 10-game rolling CSW% graph, for the visual learners:

His whiff rates showed dramatic improvements across the board. If this hitter profile can translate to MLB, then he will have really fixed something down in AAA. His effort definitely shows in his performance. With the injury to Taylor Trammell last night, we may see him sooner rather than later. If we don’t, I can keep updating this on a weekly basis until he gets called back up.

I don’t think anyone can say for sure whether Jarred is fixed for good or not. Development isn’t linear and maybe the improvements I am seeing are meaningless against big league sliders. I think his stance tweaks have improved his ability to recognize pitches, which has produced better swing decisions and more contact. When Jarred makes a lot of contact he is an excellent hitter. As an additional note, he was on the exit velocity leaderboard almost every night I looked at. He has been hitting the ball HARD. Most importantly, he has shown a significant improvement in his ability to lay off or make contact with breaking pitches.

It's time to get excited about Jarred Kelenic, Major League hitter again.