Rum Bunter Staff Predictions For The 2023 Pittsburgh Pirates: Noah Wright

Best Pitcher - Mitch Keller

It's Mitch Keller's time to shine. The former top pitching prospect had struggled for years for multiple reasons. In Keller's first year, he was extremely unlucky; the next year, he was extremely lucky, then outright was not good in 2021. 2022 was a make-or-break season for Keller, and he made the best of it, making some drastic changes and helping him become one of the National League's better pitchers down the stretch.

From May 25th through the end of the year, Keller had a quality 3.20 ERA, 3.67 FIP, and 1.35 WHIP. Sure, he wasn't a strikeout machine with a strikeout rate of just 20.5%, but he had a solid 8.7% walk rate and held opponents to an HR/9 of 0.65. Keller became a heavy ground ball pitcher, inducing a grounder nearly 50% of the time (49.9% to be exact) while holding opponents to an 88 MPH exit velocity.

So what all of a sudden changed for Keller? The first thing is he started to incorporate a sinker into his arsenal. May 25th was the first day he used it at a high rate (a third of the time) and used it less than 15% of the time in a single game just once from that point forward. His sinker was one of the best in baseball last year with -8 run value, tied with NL Cy Young winner Sandy Alcantara and outpacing American League Cy Young finalist Alek Manoah. That was one major factor, but his slider's improvement was another major factor in his better results.

For most of his career, Keller's slider consistently sat with less than 3-5 inches of horizontal break. But in mid-June, Keller made an adjustment that added nearly two feet of break and hit 16 inches of horizontal movement to the pitch. From that point forward, he threw the offering with at least 15 inches of break on average. He topped out with 22 inches of break on average with the adjusted pitch, which Baseball Savant now identifies as a sweeper.

Not only has Keller made improvements in 2022, but he's added yet another pitch. He's been throwing a low-90s cutter in Spring, and it's certainly helped him get his fair share of swings and misses. It's early, a small sample size, and Spring Training, so it means little, but he has allowed just one walk while striking out 13 in just 11 innings of work. If he can make it another above-average offering in his arsenal, Keller might just end up as one of baseball's most underrated pitchers.