Where Are Aaron Civale’s Strikeouts?

Aaron Civale is having a fantastic season thus far. Through six starts, he has a 3.20 ERA and 1.04 WHIP in 39.3 innings. He has just an 18% strikeout rate and 10% K-BB rate, though, which is why he has a 4.42 SIERA. He isn’t missing bats all that well, but instead keeping the ball on the ground with a 54% GB rate that is 8th among starters. He has never been a strikeout stud, but he had a 21% mark coming into this year and with his depth of arsenal, there was reason to believe he could improve even more.

What happened to his strikeouts?


He has switched over from a changeup to a split-change and he’s using it more often, up 7 points to 16% usage. He has also used his slider more often, up 5 points to 14%, while his cutter usage is down 9 points to 20%. They are distinctly different pitches, too, with a 5-mph velocity split and very disparate usage profiles (sliders aren’t even thrown to lefties). He has also switched from a sinker to a four-seamer as his primary fastball.

Neither changeup is a strikeout pitch so that hasn’t had any effect. The changeup had one strikeout in 18 PA last year (6%) and the split-change has 3 in 25 (12%). The cutter is a better strikeout pitch than the slider so that change is definitely impacting his rate. Plus, the cutter rate is down a smidge to 21% (-3 pts from last year). The slider literally hasn’t garnered a strikeout in 15 PA.


Civale’s swinging strike rate is down a bit from last year’s 10% peak to just 9% so far this year. The curveball has experienced the biggest dip, down 8 points to 13%, though it hasn’t really impacted his strikeout rate with the curveball which is essentially static (down 1 pt to 27%). The other big dip is with the changeup as his new split-change is 4 point lower than the straight changeup was a year ago which probably explains the small drop in strikeout rate with the change this year.

Called strikes have fallen off for Civale. He was 10th in the league last year with a 20% mark which aided the 2 point jump he saw in strikeout rate from 2019 to 2020. He is down to just 15% this year, slotting him 60th among qualified starters. The biggest reason for the drop in called strikes is the change from sinkers to four-seamers.

He generated a ton of called strikes with the sinker, but the four-seamer doesn’t generate them at nearly the same clip. A big part of that is where he works each pitch. The sinker is an in-zone pitch (59%) that he worked high and middle in the zone while the four-seamer is primarily a high zone pitch. The four-seamer is better for swings-and-misses – 4% on the sinker; 12% on the four-seamer – but obviously the switch hasn’t been enough to counter the drop in whiffs across the rest of his arsenal so he is still down on swinging strike rate overall.


Civale has been a bit more efficient this year, taking his pitches per plate appearance from 3.9 to 3.7, which isn’t a massive drop, but there isn’t a single smoking gun behind the strikeout dip so all these small issues add up. He has also seen his plate appearances that reach 2-strikes drop from 55% last year to just 46% this year. His rate of plate appearances that he gets into a pitcher count has also dropped a good bit, from 38% to 36%, pushing him from 22nd to 56th in the league. I can’t really critique guy who is being more efficient, especially with the results Civale has gotten thus far.

It is hard to say that Civale is disappointing in strikeout rate because expectations that went beyond the 21% we had seen from him prior to 2021 weren’t particularly fair in the first place. It wasn’t impossible to see some strikeout upside but expecting it would be another thing altogether. He isn’t that far from last year’s rate, either.

An extra strikeout per start (6 total) would have him right back at 22%. The host of minor changes outlined here show why he is falling short of that mark. It isn’t impossible to see him pushing back up to or over 20% the rest of the way, but if you were expecting any sort of substantial gains (I wasn’t expecting it, but definitely believed he could make a leap) you may wind up disappointed this year.

Despite his deep arsenal, he still hasn’t landed on a true strikeout pitch and part of it seems to be by design. He seems content enough to favor efficiency and weak groundball contact over a bunch of strikeouts. He is better than his 4.41 SIERA, but not quite a true talent 3.20 ERA like we’ve seen thus far. Give him a 3.60 ERA, 1.15 WHIP, and 20% K rate the rest of the way.

Paul is the Editor of Rotographs and Content Director for OOTP Perfect Team. Follow Paul on Twitter @sporer and on Twitch at sporer.

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2 years ago

I wonder if you may start to see a trend where the league is getting used to the plus velocity to the extent that the 91.4 mph average guys like Civale, as good as their secondary stuff might be, are going to underperform K% because the hitters are in essence sitting on everything, including the fastball (especially with two strikes). These newly defined “soft-tossers” can still have great results, from inducing GBs and other weak contact to end an AB (plus a reasonable amount of Ks), but may consistently underperform expected K numbers.

2 years ago
Reply to  SucramRenrut

Good thought.

I watched his last couple starts and noticed how aggressive hitters were being with him too. The Royals game especially.

As a hitter, you know a couple things about Civale: (1) he’s not going to walk you, (2) he can’t blow anything by you, and (3) he’s going to throw a first pitch called strike if he manage it.

So…pick the fastball or the curveball and look to smoke it on the first pitch. If that doesn’t work, be hyper aggressive in the zone throughout the AB. The Royals were all over him throughout the game. Plenty of soft contact, to be sure, but loads of contact.

I think Civale is a wonderful pitcher but some days he’ll get BABIP-ed to death (more so than other pitchers). And on days where he doesn’t have good feel for a major pitch of his……it’s gonna be a bad time.