Nine 2018 Pitcher Strikeout Rate Surgers — A Review

In mid-February, I used my pitcher xK% equation to highlight nine pitchers that may have strikeout rate upside for 2018. The important thing to remember is that xK% is not a projection and isn’t meant to be forward-looking. Rather, it’s descriptive, or backward looking, the same way you might think about FIP/xFIP/SIERA. I have found many pitchers who consistently over/underperform their xK% marks for whatever reason, so I never blindly use previous xK% marks as my next season forecast. That said, let’s find out how the pitchers with the greatest positive divergence between 2017 K% and 2017 xK% performed in 2018.

So the overall results were a mixed bag, with four starters enjoying the jump as predicted, while five suffered a decline. Interestingly, if I just take the simple average of the difference in strikeout rates, it’s marginally positive, so the guys who jumped, did so to a greater degree than the guys who fell. That’s a good sign since pitchers on average will see a drop in strikeout rate in Year X + 1, and yet on average, these guys saw a slight increase.

Not only did Joe Musgrove sit atop this leaderboard, but he was also traded to the Pirates, so he now gets to face the pitcher a couple of times, which typically ups a pitcher’s strikeout rate. Sadly, that didn’t happen. Of course, he did miss nearly two months with a shoulder injury (though his fastball velocity was actually up on the season), so we shouldn’t fault him for failing to raise his strikeout rate. I still think there’s upside here given his ability to generate swings and misses.

Well, duh, any monkey could have thrown a dart and landed on a higher strikeout rate for Matt Harvey than what he posted in 2017. But that wasn’t the point. My xK% equation suggested he was actually unlucky in 2017 and should have posted a better mark to begin with. He obliged this season, but remains far below his pre-injury standards.

I wondered aloud where Sean Manaea’s strikeouts went, as he dealt with a loss of velocity and a loss of bat-missing skills. Then he ended up hurting his shoulder and missing the final month of the season. Was his shoulder bothering him all season, explaining the velocity and strikeout rate decline? More than likely.

I felt really good about Sean Newcomb heading into the season given his strikeout potential, especially considering his consistently high marks in the minors. And heck, he needed to raise that strikeout rate given his horrid control. He barely improved his walk rate, but his strikeout rate slid and his SwStk% actually fell below the league average. I want to bet on a breakout, but now we have to hope he improves both his strikeout and walk rates, which is a lot to ask for. Then again, control is one skill that could seemingly improve overnight.

Dylan Bundy was a nice win, even though he torpedoed his fantasy teams’ ratios. Though his extreme fly ball tendency is scary (and my gosh, you can’t allow that many fly balls and also allow an inflated HR/FB rate), his SIERA was just below 4.00, giving him one of the largest gaps among all starters. He’ll be hard pressed to actually get his ERA below 4.00, but at his likely cost, I want to own him for the upside, especially in deep leagues.

Jake Odorizzi boosted his strikeout rate to the second highest mark of his career, but his walk rate barely rebounded, so his ERA remained well above 4.00. With his extreme fly ball tendency, there’s not much intrigue here.

Dan Straily missed the first month of the season with forearm inflammation and most of the last month with an oblique injury. In between, his strikeout rate fell to its lowest mark since 2015 while in the American League. Like Manaea, you wonder how healthy he was all year as forearm injuries are ominous.

Seriously, explain Kevin Gausman. Armed with a mid-90s fastball (though that velocity dipped below 94 mph for the first time this season), an elite swing and miss splitter, and acceptable slider, how is he posting such pedestrian strikeout rates? I though the breakout was coming when he came to Atlanta, a National League team in a much more favorable home park for pitchers, but both his strikeout and walk rates actually regressed! Sure, his ERA plummeted to sub-3.00 levels, but that was entirely due to incredible fortune, thanks to a .260 BABIP and 7.8% HR/FB rate. I’m not sure where I’ll stand on him next year and given his superficially good run with the Braves, he might appear on many a sleeper list, taking away any profit potential.

So after his strikeout rate slipped below 20% for the first time, Julio Teheran boosted it to set a new career high this year. Don’t you love it when that happens? Career low is followed by career high. His SwStk% also jumped to a career high, even though his fastball declined to its lowest velocity ever. He once again massively outperformed his SIERA, this time thanks to an absurd .217 BABIP, so I’m not touching him with a 100-foot pole next year.