Pittsburgh Pirates’ starter Mitch Keller has yet to have any sort of normalacy in his young MLB career, but could 2021 be a more regular season for him to breakout?
Just a few years ago Mitch Keller was one of the premier pitching prospects in all of baseball, as well as being the highest rated prospect the Pittsburgh Pirates had. So far, he’s pitched in two seasons, but hasn’t had any normalcy in either season. 2021 may be the first season Keller not only pitches under more regular circumstances, but also puts up more normal numbers.
Keller made his debut in 2019 where he pitched in 11 games and tossed 48 innings. He had an unsightly 7.13 ERA, but almost every measure in the book said he was unlucky to a massive degree.
He had really strong ERA estimators coming in with a 3.19 FIP, 3.47 xFIP, 3.78 SIERA while having a solid 4.00 xERA and 4.03 DRA. He also had an outstanding 28.6% strikeout rate and 7.0% walk rate. With a 1.13 HR/9, he was also above average in the long ball department. He was also above average in exit velocity (87.6 MPH) and hard hit rate (35.3%).
Keller was severely hurt by a .475 batting average on balls in play. In the history of baseball, no pitcher has ever had that high of a mark in at least 40 innings pitched. He’s also the only pitcher ever to have a BAbip above .450 in 40+ innings of work. He was really a 3.50-3.80 ERA pitcher, but every little blooper, weakly hit ground ball was able to fall into no-mans land or was just out of the reach of a fielder.
This past season, Keller swapped out his extreme unluckiness for extreme luckiness. The right-hander had a 2.91 ERA, but walked more batters than he struck out (16/18 K/BB Ratio), saw his home run rate spike to 1.66, his exit velocity rise to 88.5 MPH and hard hit rate jump to 42.3%. Among, FIP, xFIP, SIERA, xERA and DRA, his lowest ERA estimator was xERA at 6.07.
Through 21.2 innings, Keller somehow managed a .104 BAbip. While everything essentially went wrong for Keller in 2019, everything went right for him in 2020. Just like he set a record for the highest BABip among single seasons where a pitcher threw at least 40 innings, he also holds the lowest ever single season BABIP in a season where a pitcher threw at least 20 innings. Not only was it an unusual season for him in terms of stats, but he also was injured for a few weeks during the strange 60-game sprint season.
Now this is a very small sample size. He’s pitched less than 70 innings. We’ve yet to see what Keller can do under the tutelage of new pitching coach Osar Marin. The last time Keller pitched a decent amount of innings was at Triple-A in 2019. In 103.2 innings, Keller had a 3.56 ERA, 3.60 FIP and 1.24 WHIP. Not only did he put up great bottom line numbers, but he also had a 24.2% K%, 8% walk rate, .78 HR/9 rate, 3.87 xFIP and 3.38 DRA.
Keller was arguably the best Triple-A pitcher in 2019. He was 4th in ERA and opponent average, 1st in FIP, xFIP, strikeout rate, HR/9 and 8th in K/BB ratio among Triple-A pitchers with at least 100 innings under their belt throughout the entire season.
Keller is still just 24-years-old. His fastball and curveball are both 55-grade pitches and his slider is a 60-grade pitch. He’s always struggled with his change up, but three plus pitches are a good thing to have. In 2019, he was well above average in terms of movement to his two breaking pitches while having well above average spin rate on his fastball, curveball and slider.
Keller has yet to have anything normal happen to him in his MLB career and that’s all he might need in order to breakout. He could also benefit from improved defense from the Pittsburgh Pirates.
Bryan Reynolds took major steps forward with his glove in 2020. The Pittsburgh Pirates could lineup Ke’Bryan Hayes and Cole Tucker on the left side of the infield to create one of the most defensively sound left sides of the infield in baseball.
Josh Bell, who was one of the worst players in baseball defensively, will be replaced by a much more defensively competent duo of Colin Moran and Phillip Evans. Let’s also not forget he’ll be regularly throwing to Gold Glove finalist Jacob Stallings, who has 8.3 framing runs and leads all in NL backstops DRS (+21) the past two years. Another thing of note is that many of the Pirate pitchers had shown a lot of improvement, namely Joe Musgrove, Steven Brault, Richard Rodriguez and Chris Stratton, under Oscar Marin. Plus in terms of pitch value/100, only his change up was below average. Overall, things are working in Mitch Keller’s favor to have a breakout 2021 season.