Ten 2018 Pitcher Strikeout Rate Decliners — A Review

Yesterday, I reviewed my preseason list of nine potential strikeout rate surgers. Today, let’s find out how the 10 pitchers I identified as potential strikeout rate decliners actually performed.

Potential 2018 K% Decliners vs Actuals
Name 2017 K% 2018 K% Diff
Jose Quintana 26.2% 21.4% -4.8%
Ivan Nova 16.7% 16.7% 0.0%
Chris Sale 36.2% 38.4% 2.2%
Noah Syndergaard 27.4% 24.1% -3.3%
Corey Kluber 34.1% 26.4% -7.7%
Madison Bumgarner 22.4% 19.8% -2.6%
Clayton Kershaw 29.8% 23.9% -5.9%
Jake Arrieta 23.1% 19.1% -4.0%
Carlos Rodon 25.6% 17.6% -8.0%
Carlos Martinez 25.3% 22.5% -2.8%

Well daaaaaamn this was quite a successful list! Eight of the 10 pitchers suffered a strikeout rate decline and they averaged a drop of 4.9%….that’s huge! Only one of the pitchers even improved his strikeout rate, as the other non-decliner was essentially even. Judging from past reviews, I believe I’m far superior projecting declines than breakouts. That makes sense as breakouts generally occur with no prior notice, with little to go off of to predict such a performance spike.

Jose Quintana was the most obvious strikeout rate decline call, but even Steamer failed to project the degree of decline, as it forecasted a 24.2% strikeout rate (I was at 22.5%). What’s interesting is even a full season in the National League for the first time couldn’t stave off regression. This is what happens when you stink at generating whiffs. You have to rely on called and/or foul strikes and those are less sticky year to year than the swinging variety.

His second full season in the National League was no better for Ivan Nova’s ability to miss bats. He did raise his SwStk% marginally, but he was basically the same pitcher he’s always been.

That’s kind of hilarious. Anyone on Earth and every projection system would have figured Chris Sale would suffer a strikeout rate decline off his fantastic 2017 mark (even if minor), but instead, he actually raised his rate even higher. In fact, his insane 38.4% strikeout rate was the highest mark among all pitchers who threw at least 150 innings since 2000! Doing that while limiting his walk rate to just 5.5% is just not human.

I was surprised to find Noah Syndergaard’s name on this list, but he obliged and made his appearance look like the right move. With another 13%+ SwStk% and a fastball that once again averaged more than 97 mph, it’s shocking that his strikeout rate was only a couple of percentage points above the league average. It’s also absurd that a pitcher with the quality of stuff that he possesses owns a career .314 BABIP.

Yeesh, while my equation suggested that Corey Kluber was in for a strikeout rate fall, I didn’t see this. Then again, this regression was literally right back to where he was at in 2016, before the sudden spike in 2017. Now 2017 looks like the clear outlier rather than a new level of performance. He’s still top notch, but heading into his age 33 season and with a pathetic sinker with respect to inducing whiffs, there’s more risk here than you might think.

Boy did xK% call it with Madison Bumgarner, who even after posting a down 2017, was still seen as having additional downside. His skills have been declining rapidly, but he’s still under 30 and his fastball velocity has remained relatively stable the last three years, so I’m not sure the cause here. Unfortunately, with a 3.26 ERA vs 4.42 SIERA, he’ll likely still be valued as an elite option, which means much more downside than profit potential.

And another prescient call on Clayton Kershaw, who was already coming off his lowest strikeout rate since 2013. xK% saw further downside and his whiff-inducing skills ultimately vanished. Likely a big reason for that is a fastball that fell below 93 and 92 mph for the first time, settling at just 91.4, after sitting between 93.1 and 94.4 mph his entire career. His health has been a major issue these past couple of years, so you wonder how much that has affected his performance. Amazing, his 2.73 ERA, while elite, was his highest mark since 2010! He might come the cheapest he has in many, many years, making him a reasonable high risk/high reward draft day buy.

Jake Arrieta’s skills are in freefall and he has clearly lost the magic of his early Cubs days. With a rapidly declining SwStk%, I’m not betting on much of a rebound.

I said I wouldn’t touch Carlos Rodon given the shoulder injury and appearance on this list, and I was right to do so for the most part. His strikeout rate plummeted, but he did manage to outperform his SIERA by nearly a run, while posting a positive-valued WHIP. He ended up not doing the type of damage his ratios could have done with neutral luck, but that .242 BABIP ain’t going to last.

Even making 15 relief appearances wasn’t enough for Carlos Martinez to avoid strikeout rate regression. The velocity on both his four-seamer and sinker were down dramatically to career lows, which is not what you want to see from a 26-year-old. How much longer can he outperform his SIERA?

We hoped you liked reading Ten 2018 Pitcher Strikeout Rate Decliners — A Review by Mike Podhorzer!

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Mike Podhorzer is the 2015 Fantasy Sports Writers Association Baseball Writer of the Year. He produces player projections using his own forecasting system and is the author of the eBook Projecting X 2.0: How to Forecast Baseball Player Performance, which teaches you how to project players yourself. His projections helped him win the inaugural 2013 Tout Wars mixed draft league. Follow Mike on Twitter @MikePodhorzer and contact him via email.

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Wow! Nice work. Looking forward to the 2019 list.