Mitch Keller: Is it Time to Give Up?
By Ryan Simpson
Mitch Keller was the last of the draftees from the pitching overhaul by Neal Huntington. Huntington targeted highly touted arms from 2010 to 2014. Out of the 29 picks Huntington had in that span, he used 14 on pitchers. Arms such as Jameson Taillon, Nick Kingham, Gerrit Cole, Tyler Glasnow, Mark Appel and Mitch Keller were selected to join the organization. Walker Buehler was also picked by the Pirates but didn’t sign. That’s a story for another time.
These pitching prospects all showed some level of promise in the minors. Taillon, Glasnow, Kingham and Keller were all in the top 15 for organizational prospects ranked by MLB.com going into the 2015 season. The Pirates had some hammers and it was only a matter of time before Pittsburgh had a deep, effective rotation.
Taillon and Cole showed signs of brilliance, further cementing their status as the next generation of talent. Kingham had his struggles and Appel never signed with the team. That brings us to Glasnow and Keller. The season before Glasnow got the call to the majors, he was ranked as the seventh overall prospect in baseball. Keller was ranked 16th overall before he got the call so the pressure was on these two to perform.
Alas, Glasnow wasn’t nearly as dominant in Pittsburgh as he was in the minors, and thus was now famously traded at the 2018 deadline to Tampa Bay, along with Austin Meadows and Shane Baz for Chris Archer. Glasnow went on to become an absolute stud.
Keller is now on the same trajectory as Glasnow: a young gun failing to reach the same level of success in the majors that he did getting to the show. Should Pittsburgh’s front office give up on Keller like it did Glasnow? Should Pittsburgh’s fans give up on Keller?
Let’s look at Keller’s stats compared to Glasnow’s from his time in a Pirates uniform.
You can see that they are not at the same number of innings pitched, so I transformed Glasnow’s numbers to match Keller’s IP. Now, taking a look at these numbers you do see a lot of green on Glasnow’s side. The most intriguing part to me is what categories Keller is better is to this point: fewer walks, more strikeouts and a higher strikeout per nine innings. Glasnow is now a guy who pops up on PitchingNinja’s Twitter feed every start he makes for making a guy look silly; Keller is striking out guys at a higher rate than his comparison here. Can Keller transform himself as well as Glasnow did in Tampa? Let’s dig a bit deeper…
Let’s compare Keller to the rest of the league now.
Let’s compare Keller to the rest of the league now. Looking at this new dataset, we see that Keller is below average in almost every stat. He is above average at limiting home runs and strikeout percentage, which is a decent start. One takeaway here is that Keller’s allowed BABIP is .376 while the league average is .295. That gap is ENORMOUS. The Ringer’s Ben Lindbergh wrote a great piece about Keller’s uncanny rate to give up hits in a piece last year, which I will leave at the end.
Another takeaway from this data is that when Keller gives up a hit, it goes for extra bases. hitters are slugging .502 against him. For reference, Andrew McCutchen slugged .508 in his 2013 MVP season. Keller struggles to limit the bleeding. He can let give up hits, but let them be singles and not for extra bases.
Let’s look at how Keller’s performance as fared this year.
Here we are looking at Keller’s Baseball Savant percentile ranks up against the next most exciting young arm in the rotation in JT Brubaker. Classic color rules apply as the darker blue is bad, closer to white is average, red is great. Once again, Keller is below average in almost every stat and Brubaker is clearly the better pitcher this year. I was kind of shocked once I got near the bottom of the chart when you can see why Keller struggles; a 10% whiff rate paired with a 35% chase rate is abysmal. The hitters are reading Keller like a book and simply not chasing his pitches. When they are chasing, they are rarely missing at that 10% clip.
Meanwhile, Brubaker is at a 54% whiff rate and an elite 90% chase rate. Brubaker is just better at getting hitters to chase pitches and making them miss. Does this lead to questions of how to “fix” Keller? This is where we get to play pitching coach alongside Oscar Marin.
Finally, let’s look at the arsenal we are working with here and how we can use it to our advantage. Velocity will always be king in the MLB and as we can see, Keller’s fastball velo is right up there with the league average. Looking at his secondary pitches, we see his slider and changeup are above the average. His curveball is slightly below average, but that’s ok. Looking at his trends over his career, Keller’s usages have been fairly consistent. In terms of usage, his four-seam is his number one pitch; his true secondary pitch is his slider with his curveball and changeup bringing up the rear.
So, from a coach’s eye we have a guy with plus velocity on three of his four pitches, consistent usage rates and poor performance across the first 25 games of his MLB career. What do we look to next? We look at how each pitch is performing and where the pitcher is throwing each pitch type. I gather data from Baseball Savant comparing Keller’s 2019 season to 2021 as he experienced a pitching coach change in that time frame.
We see a slight dip in curveball velo which is good in my eyes as now his curve is his “softest” pitch while the rest of this stuff is “hard” in the high-80s to mid-90s. Now is where we get a clear picture of what is happening with Keller. As mentioned, he is not getting batters to swing and miss in general and it’s even more clear when broken down by pitch type. He is simply not getting swings and misses. He lost the ability to strike batters out with his slider and curveball as both pitches are producing fewer Ks than his 2019 season. No matter what pitch he is throwing, he is getting ROCKED.
Time to look at pitch locations (still looking ’19 vs. ’21).
His fastball is virtually the same, but those red blobs in the upper third of the strike zone scare me; that’s dinger city in this era of baseball. His slider is catching more of the zone now than in 2019, which is fix No. 1 for Keller: make this slider your chase pitch. It has above average velo and you obviously trust it looking at how often you throw it.
Go talk to Kyle Crick and make your slider absolute filth. His curveball is pretty similar as well as we can see that his misses are more horizontal than vertical this season. No complaints there. Now, this changeup is a mystery to me. He rarely throws it, but he can throw it up into the 90s??? I would tell him to use this pitch more as well. He is locating it well in both his charts here, I think it would just need some time to pair with his fastball. The top 5 players in the MLB for changeup velocity are Sandy Alcantara, our old buddy Tyler Glasnow, the reigning, defending Cy Young winner Jacob deGrom, Corbin “57 strikeouts before giving up a walk” Burnes and MITCH FREAKIN’ KELLER. Develop that changeup and let it ride.
I’m not ready to give up on Keller just yet. He is 25 years old in an organization that just had a complete overhaul on management and he is now working with a catcher who is among the best in the MLB. There is hope. The pieces of an ace are there, Keller just has to put them together and rekindle that fire to become the baddest arm in Pittsburgh.