2018 Spring Training Starting Pitcher K% Surgers

Almost exactly six years ago, I published a study that suggested pitcher spring training strikeout and walk rates had some predictive value for the upcoming season. Not a lot, of course, but there was definitely something there that shouldn’t be ignored like the rest of spring stats. I looked at all pitchers who have logged at least 15 innings this spring, and then compared their strikeout rate to the Pod Projection strikeout rate. Let’s discuss the 10 starting pitchers that enjoyed the largest spikes. I’ll take a look back at the end of the season to see if these surges really were prescient.

2018 Spring K% Surgers
Player K% Pod Projected K% Diff
Jack Flaherty 38.1% 21.4% 16.7%
Blake Snell 39.7% 24.7% 15.0%
Madison Bumgarner 36.1% 24.2% 11.9%
Mike Clevinger 34.7% 24.0% 10.7%
Amir Garrett 30.9% 20.5% 10.4%
Paul Blackburn 23.0% 13.0% 10.0%
Brent Suter 28.4% 18.5% 9.9%
Kyle Hendricks 31.5% 21.9% 9.6%
Tyler Glasnow 33.8% 24.6% 9.2%
Sal Romano 29.0% 19.9% 9.2%

This is a pretty fun list!

At the top of the list is the dominant Jack Flaherty, who will get a shot in the Cardinals rotation, at least until Adam Wainwright returns from the DL. We have no velocity readings to see if his fastball has gained steam, but reports indicate he’s been working on his sinker, which if much improved, could help explain the performance leap. The sinker was his third most thrown pitch and it generated whiffs at an average rate in his 21.1 innings, but it was his slider that was ridiculously elite. Flaherty posted pretty good strikeout rates in the minors, but they didn’t typically come with big SwStk% marks. I’m curious to see how he performs and if he forces the Cardinals to make a tough decision.

I decided to throw Blake Snell’s name into my bold pitcher league leaders for strikeouts and I have to admit that his spring dominance influenced my choice. We also have no velocity readings here and no word of a new pitch. But, he routinely posted strikeout rates above 30% in the minors with tons of swinging strikes. That’s because all of his non-fastballs are either good or elite. Someone please trade me Snell. Better yet, hope he gets off to a slow start thanks to a high BABIP or HR/FB rate or a low LOB% and then steal him from his impatient owner.

Though Madison Bumgarner is hurt, the spring strikeout rate was a good sign after his 2017 regular season strikeout rate tumbled to its lowest mark since 2010.

Man, Mike Clevinger is doing his best to prove that last year’s elite strikeout rate, which was better than anything he had posted previously, was real. Want to fall in love? Check out his Pitch Type Splits. Look at these SwStk% marks!

Mike Clevinger SwStk% By Pitch Type
Pitch SwStk%
Slider 23.4%
Changeup 19.0%
Curveball 20.7%

To throw just one should be good enough, two would make a pitcher dominant, but three?! That’s like an auto-best pitcher in baseball. Of course, control is holding him back, but that’s the easiest skill to improve upon. I wish the hype on him wasn’t so deafening, inflating his draft day cost, because I managed to purchase ZERO shares.

So Amir Garrett went from fantasy irrelevant to intriguing sleeper. That’s because unlike the others so far, we actually do have a velocity figure from about a month ago when he was throwing 95-97. That’s significant, because he only averaged 91.6 mph last season and maxed at 97.1. If he is truly now a mid-90s guy, that changes everything. He’ll beat his computer projections for sure and is a great target in NL-Only leagues. He also becomes a pitcher to monitor in mixed leagues.

Sadly, Paul Blackburn was placed on the disabled list with forearm discomfort, which is always an ominous injury. Luckily, it doesn’t seem like a precursor to TJ Surgery and he is expected back sometime in May. In 58.2 innings during his Athletics debut last season, he somehow managed just a 9.2% strikeout rate. And he wasn’t even shelled! Even with all those balls in play, he posted a sterling 3.22 ERA. Since he’s an elite ground ball guy and possesses good control, a high teen strikeout rate would make him quite exciting.

Brent Suter posted a 3.42 ERA over 81.2 innings last season, despite featuring a fastball that averaged just 86.2 mph! Craziness. He generally posted ugly strikeout rates in the minors, usually falling into the mid-to-high teen range. Given his poor velocity and the fact that only his slider generated a double digit SwStk% last year, it’s hard to believe a breakout is imminent.

Kyle Hendricks has been posting at or above league average strikeout rates since his sophomore season, despite terrible fastball velocity. More incredible, his fastball velocity fell two mph last year, and yet his results barely slipped. The good news is that in his second outing of the spring back on March 5, he was back to throwing near 88 mph, a complete rebound from his down 2017. I’m confident he’ll continue to significantly outperform his SIERA.

I was bummed to learn that Tyler Glasnow is going to open the season in the Pirates bullpen, as his spring performance reminded us of his strikeout upside and made us forget about his underwhelming, sub-20% mark last year. Glasnow owns premium velocity, as he averaged 94.6 mph with his fastball last year, maxing just below 100 mph. But already at the end of February, Glasnow had touched 100 mph and sat consistently 97-98 mph. Obviously, his strikeout potential has never been in question, so we’ll have to wait to see if and when he improves his control enough to let those strikeouts lead to a breakout. Assuming his bullpen work is strong, I’m immediately picking him up in all leagues when he moves back into the rotation.

Sal Romano is a surprise name on here, as just once did he post a strikeout rate above 20% in his professional career. The thing is, he has teased us before. In fact, last spring training he did the very same thing — he posted a 30.9% strikeout rate then, just to post a worse than average 19% mark over 16 starts. So clearly that surge wasn’t predictive last year. Will it be this time? He does throw 95 mph and compliments that heat with a slider/curve that was excellent at inducing whiffs last year. He needs to dramatically improve the changeup, but it’s clear he has the building blocks to quickly improve.

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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Suter allowed some of the softest contact in 2017 — 83.8mph, 15th best among pitchers with 100+ BIP.