Ivy League Cubs

By: Jake Russell

The Cardinals have just agreed to terms with relief pitcher Kenyan Middleton, per Robert Murray.

Middleton began 2023 with the White Sox and was traded at the deadline to the Yankees for Juan Carela. It was his most successful season to date, as he put up a 3.38 ERA (78 ERA-), and marked the first time he eclipsed 50 innings since his rookie year in 2017.

Middleton had a 30.2 Strikeout%, easily the best mark of his career, and a career-high K-BB%. Middleton also had a 93rd percentile ground ball rate, at 56.5%. This GB% was also a career-best for the veteran relief pitcher.

In 2023, Middleton relied on 3 pitches–a Changeup, Slider, and Four-seam Fastball. The Fastball graded out as his best pitch per Eno Sarris’ Stuff+ model, at a 114. It averaged nearly 17 inches of Induced Vertical Break and 8.1 inches of arm-side run. He also averaged 95.5 MPH of velocity on his fastball. In my opinion, a very large contributor to his success is that he averaged 6.8 feet of extension last season–that fell in the 81st percentile, and likely is a large part of why the pitch is so effective. It got whiffs 33% of the time last year, which is very good for a Four-seam fastball! (League average is roughly 20%). It’s also a pretty flat pitch–it enters the zone at -4.4º. The average four-seam fastball enters the zone at -4.8º (which is also known as Vertical Approach Angle). Essentially, the closer to 0, the flatter the pitch when it gets to the zone.

I am a little surprised that Middleton’s ground ball rate was so good last season, given how much vertical movement he gets on the fastball, and how flat it is approaching the zone. (He also had a 32.9% career ground-ball rate before 2023, so perhaps this is partially confirmation bias, but it doesn’t seem like he made any huge adjustments in 2023). Ground-ball rate on his fastball was 11.5% in 2022, which seems much more appropriate than the 42.1% it experienced in 2023.

All that being said, Middleton does have pretty good stuff, and, pending contract details, I like this move for the Cardinals. His changeup and slider are both pretty solid, though even both pitches get a lot more carry and are a lot flatter approaching the zone than average. If I had to guess, this will be a one-year deal worth around 7-8 million dollars, and that is solid value for one of the best relievers left on the market. I do expect some regression to the mean for Middleton in 2023, but, as I said, he does have good stuff and this could be potentially a very good pickup.

Picture Credit: Kevin C. Cox, Getty Images