Reviewing The 2017 Starting Pitcher Strikeout Rate Upsiders

At the beginning of January, I used my xK% equation to identify six starting pitchers with significant strikeout rate upside in 2017. Let’s see how these pitchers actually performed.

Added to the table is the Steamer projected strikeout rate. If the best projection system also forecasted a strikeout rate surge, then xK% didn’t really add any additional value in these instances.

Well gosh, that was a terrible showing! Amazingly, every single one of these pitchers suffered a strikeout rate decline this year. All of them posted xK% marks significantly above their 2016 marks, which alone doesn’t automatically mean upside in 2017. The assumption is the underlying skills driving that xK% will mostly remain intact.

Checking in on the Steamer projections, the system projected an increased strikeout rate for five of the six pitchers too. The only one it projected decline for was Dylan Bundy, and he actually came closest to his 2016 mark.

This is a mostly boring group of pitchers to discuss, but we’ll do so anyway.

So a move back to the NL wasn’t enough to prop R.A. Dickey’s strikeout rate back up. It’s amazing he’s still pitching at age 42, but hey, knuckleballers don’t follow the rules! He’s seemingly still acceptable enough to stick as a back-end starter and innings eater.

Clay Buchholz started all of two games before succumbing to the Pod injury curse. Sorry buddy, should have warned you.

So was it really just all in the velocity decline for Jordan Zimmermann? Obviously we expected a strikeout rate decline upon his move to the AL in 2016, but this is ridiculous.

Dylan Bundy reintroduced his slider/cutter, but it had no effect on his strikeout rate, despite boosting his SwStk%. Encouraging though is that sizzling second half strikeout rate that sat at nearly 27%. A high fly ball rate certainly limits his upside, but he’ll enter 2018 as a sleeper once again.

Aside from the higher xK%, Mike Foltynewicz’s high octane fastball also provided hope for a strikeout rate surge. Sadly, it didn’t come to fruition. His fastball does get whiffs, and while his slider is fine, his curve wasn’t very good. He also stopped throwing strikes, which makes it difficult to strike out Major League hitters. At this point, he’s a “close your eyes and cross your fingers hoping the light bulb suddenly illuminates” kinda guy.

In his 19 starts in 2016, Blake Snell did exactly what we expected — punch out lots of hitters and also walk lots of hitters. He did a little less of both in 2017 and also spent some time back at Triple-A. The good news is he was better upon his return from the minors in late August, and he struck out more than a batter per inning in September. He’s sure to be a popular sleeper in 2018 and rightfully so with his strikeout potential. Once again, his pitch type splits should generate plenty of excitement with all three of his non-fastballs generating double digit SwStk% marks, including a slider and curve in the low-20% range.