Nine 2018 Pitcher Strikeout Rate Surgers

I’ve spent nearly the entire off-season discussing hitters, as Statcast and xHR/FB rate took over my life. Let’s move on to pitchers for now, and begin with another of my xMetrics, xK%. I updated the metric’s coefficients last season and it’s probably the best xEquation out there given its sky high adjusted R-squared.

So let’s dive into the fantasy relevant starting pitchers who posted actual strikeout marks significantly below their xK% marks. I plucked the names of guys whose xK% marks exceeded their actual K% marks by at least 2%, suggesting serious upside for this season, assuming they maintain their xK% components.

Joe Musgrove sits atop the throne, sitting far out in front. While he posted just an averageish strikeout rate, he threw a ton of strikes and induced whiffs at a strong clip. That alone would have resulted in a nice jump in strikeout rate this season, but there’s a bonus — he was traded to the Pirates, so now he gets to call the National League home and get a chance to face the pitcher two or three times a game. He’s a prime sleeper in all formats.

Yeah, yeah, it’s debatable as to whether Matt Harvey should still be considered “fantasy relevant”, but I included him here to point out that he appeared to be quite a bit unlucky in 2017. Of course, even with neutral luck, his strikeout rate would have still represented no such rebound off his injury shortened 2016 and a precipitous decline from the seasons prior. Check out that pitiful S/Str (swinging strike) rate! Obviously this was all health related, so one would think that if he could regain his former velocity, everything else will fall back into place. Might as well take the gamble as a reserve round pick in a 12-team mixed league and follow his spring.

Sean Manaea has posted big strikeout rate marks in the minors, but he hasn’t been able to nudge his K% above 21% with the Athletics…yet. That should change in 2018. Both his changeup and slider have generated swings and misses at above average clips, so there’s real upside here. As with many pitchers, health is going to be key, since Manaea battled shoulder issues during the season and a forearm injury in 2016.

Interestingly, Sean Newcomb is the second straight left-handed throwing Sean on the list. Newcomb has always enjoyed strong strikeout rates in the minors, but his control has been an issue. And while one may look at a 23.7% strikeout rate and not expect much better, xK% hints at additional upside. That’s a premium S/Str mark, especially for a rookie. If he starts throwing even more strikes, a major breakout is his for the taking.

Dylan Bundy posted just an 18.9% strikeout rate in the first half, but a more impressive 26.9% mark in the second half. The explanation is easy — he threw his slider 19.3% of the time in the first half, but jacked that up to 27.1% in the second. And that slider is devastating — it generated a SwStk% of 24.4%! So xK% hints at upside completely ignoring the change in pitch mix, then you have additional upside if he sustains that bump in slider usage.

Jake Odorizzi traded called strikes for swinging strikes, which is always a good move. Except that it didn’t actually boost his strikeout rate. In fact, his strikeout rate just hit a career low, despite an xK% that rose for the second consecutive season. His control also disappeared, so if that returns, there’s even more upside here.

I believe it was back in 2012 when Dan Straily led the minor leagues in strikeouts. He posted strikeout rates above 30% during stints at Double-A and Triple-A. Unfortunately, those strikeout rates have not carried over to the Majors, though he is coming off a career high. He relies on an excellent pair of offspeed pitches in his slider and changeup, both of which generated SwStk% marks in the high teens. However, it’s worth noting that he has underperformed his xK% in three of four seasons, and all these of those were by at least 1%. He’s probably in that small group that is doing something, or not doing something, missed by the equation.

Maybe the Orioles do have something to look forward to from their pitching staff! Kevin Gausman is the second Baltimorian to appear on the list, and his strikeout rate splits look almost identical to Bundy’s. His splitter is his signature pitch, but for whatever reason, he threw it just 17.6% of the time in the first half. In the second, he upped its usage to 24.1%. Gausman has underperformed his xK% in each of the last four seasons, so like for Straily, there must be something being missed. But he hadn’t underperformed as drastically as he did in 2017, plus he clearly figured something out in that excellent second half run.

This is the third straight season that Julio Teheran has underperformed his xK%, but 2017 represented the most stark underperformance. While his strikeout rate collapsed, his xK% was nearly identical to his 2014 mark and not significantly below his other seasons. So, this wasn’t as big a decline as it may appear. I would never be confused for a Teheran fan, but it’s possible he is undervalued coming off a highly disappointing year.