2020 Forecast — Starting Pitcher K% Decliners, A Review

Last week, I reviewed my starting pitcher K% surgers list, so today, I’ll review my starting pitcher K% decliners list, which was assembled using my pitcher xK% equation. Strikeout rates tend to bounce around throughout the season, so it’s pretty silly to be evaluating the accuracy of this list considering the pitchers only made 11 or 12 starts. But it’s all we have, so let’s get to it.

K% Decliners
Name 2019 K% 2019 xK% Diff 2020 K% 2020 K% – 2019 K%
Tyler Glasnow 33.0% 28.9% 4.1% 38.2% 5.2%
Gerrit Cole 39.9% 36.4% 3.5% 32.6% -7.3%
Aaron Civale 20.3% 17.2% 3.1% 22.1% 1.8%
Frankie Montas 26.1% 23.3% 2.8% 25.3% -0.8%

Just like the surgers, this list went 2 for 4. Of course, one of the names on here was super obvious, as no one needed an equation to guess that Gerrit Cole would have an extremely difficult time posting a 39.9% strikeout rate again! Sure enough, he was the list’s largest decliner, but still strong with a mark over 30%.

With improved control and an elite curveball he continues to throw more and more frequently, Tyler Glasnow has been performing the way we originally hoped he would back when he was a top prospect. However, he has struggled with the long ball during three of his last four seasons, resulting in ERA marks significantly higher than his SIERA. The biggest key here is his health, though, as he has only exceeded 100 innings once, and his entire career spans just 315 innings, which is essentially a full season and a half. So all his luck metrics are meaningless, as the sample size is far too small to conclude anything. What looks certain though is that if your leaguemates are only willing to pay for a 4.00 ERA pitcher, quietly bid the extra buck or steal him after his ADP and snicker to yourself.

As alluded to earlier, Gerrit Cole was an obvious regression candidate given the height his 2019 strikeout rate reached. What was actually pretty amazing is that even his xK% was 36.4%, which you don’t see very often. Typically xMetric equations don’t yield extreme marks, so normally a player would have to be superhumanly good to end up with such a high mark, but Cole managed to do just that in 2019. The magic didn’t last, of course, but he was still elite once again this year, despite a bout of gopheritis.

I wasn’t a fan of Aaron Civale’s sleeper status heading into the season, noting his enormous ERA-SIERA gap, plus his unimpressive xK%. Sure enough, he ended up increasing his SwStk%, which lead to a jump, not fall, in strikeout rate, and yet, his ERA still skyrocketed to exactly match his 2019 SIERA! So no, Civale didn’t prove to have some sort of ability to consistently induce soft contact as his low BABIP and HR/FB rate in 2019 may have convinced some. Although his ERA spiked, his SIERA actually improved thanks to the strikeout rate increase, along with a drop in walk rate. I think those are reasonable expectations, making him a decent AL-Only guy, and streaming candidate in mixed leagues, but nothing more.

After just a 15.25 strikeout rate in 2018, former prospect Frankie Montas had a big skills-supported breakout in 2019, led by a strikeout rate surge. My xK% equation didn’t totally believe it, though, so combined with his SIERA outperformance, and unlikely-to-be-repeated walk rate, I was clearly out on him at his price. That turned out to be the correct move, as his skills took a nosedive and his ERA more than doubled. A lot of that looks like small sample randomness, as his LD% jumped, fueling a BABIP increase, while his HR/FB rate rose as well. When you watch him pitch, it’s pretty clear that his stuff is superb, so he’s a perfect buy low target.

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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Thanks for all your great work Mike! Based on what you said above, am I right that you’d be betting the under on Glasnow’s 171 IP 2021 forecast by Depth Charts? Steamer and THE BAT are also at that number and I’m having trouble understanding why.