Pitcher Mitch Keller
2019 season ending ranking: 26
2020 preseason ranking: 39
It’s a bit of a surprise to see the Pirates’ best prospect fall 13 spots. After all, Mitch Keller, 23, performed very well in Triple-A, and even was semi-decent at the major league level.
Last season in Indianapolis, the right hander pitched to the tune of a 3.56 ERA, 1.24 WHIP, and 3.60 ERA in 103.2 innings. Despite playing in a league where there were almost 60 players with a slugging of .500+, Keller had a 0.78 HR/9, which was the second lowest in the International League. He also ranked fourth in ERA, first in K/9 (10.68), and first in FIP.
Although his Major League ERA and WHIP looked awful on the surface (7.13 ERA, 1.83), he still had a strong 4.06 K/BB ratio, and was extremely unlucky, and even that might be an understatement. He somehow managed a .475 opponent batting average on balls in play, which, for starters, is 100% unsustainable. He still carried a 3.19 FIP, and 3.78 SIERA (or skill interactive ERA), which both are comparable to some no-name starter Clayton Kershaw (3.10 FIP/3.77 SIERA). I have previously went much further into detail of how unlucky Keller was in his major league debut innings, which you can read here: Mitch Keller’s Unlucky 2019, And Why He’ll Be The Team’s Ace By The End Of 2020
Keller is still given great overall grades for his pitches. MLB.com gives his fastball a 65 grade, and his curve a 55 grade, while his slider and change up are given 50’s. He is also given a 50 grade for his control and is an overall 55. Just for reference, 50 is considered the mean in terms of prospect tool grades.