Starting Pitcher SwStk% Decliners — Through May 22, 2023

Yesterday, I reviewed and discussed the starting pitchers who have raised their SwStk% marks the most compared to 2022. Now let’s flip to the pitchers whose SwStk% marks have declined most. All else being equal, a lower rate of whiffs should result in a low strikeout rate and a higher ERA.

SwStk% Decliners
Name 2022 K% 2023 K% 2022 SwStr% 2023 SwStr% SwStk% Diff
Dustin May 22.8% 18.2% 12.9% 6.0% -6.9%
Andrew Heaney 35.0% 25.7% 17.0% 10.6% -6.4%
Hayden Wesneski 22.4% 16.7% 12.7% 8.2% -4.5%
Wade Miley 18.4% 14.0% 10.8% 6.8% -4.0%
Bailey Falter 22.3% 17.0% 11.7% 7.9% -3.8%
Corbin Burnes 30.5% 21.5% 15.1% 11.8% -3.3%

I have questioned Dustin May’s performance all season, and sure enough, he was placed on the IL last week with an arm injury. It’s anyone’s guess if this was bothering him all season and it finally got to the point that he couldn’t pitch anymore, or if it truly first cropped up during his last start. With a career low SwStk% and strikeout rate, it would certainly make sense that his arm hasn’t been right all year, but who really knows. With microscopic BABIP and HR/FB rate marks, he was due for some serious ERA regression, so at least fantasy owners get to avoid a major ERA increase for the time being.

Last season, Andrew Heaney posted the highest SwStk% and strikeout rate of his career, thanks to a spike in fastball velocity. This season, his velocity is back around his 2021 level, and just once has he averaged a velocity that matched what he averaged all season last year. Furthermore, he has cut down on his slider usage, the pitch he introduced last year that was so dominant, generating an elite 24.1% SwStk%. Not only has he thrown it less, but its SwStk% has plummeted to the low teens. It seems pretty clear now that last year was the outlier, unless he could regain that velocity.

Despite higher fastball velocity, Hayden Wesneski’s strikeout stuff disappeared this year, and it earned him a demotion to Triple-A. His minor league track record has been decent enough, but nothing to get too excited about. However, a higher velocity Wesneski might be better than how he has performed in the minors, so I would still keep an eye on him if/when he returns and watch that velocity.

Wade Miley continued to confound the ERA estimators, even as his ability to make batters swing and miss has disappeared. He recently hit the IL and is expected to be out for up to two months. I would not roll the dice with such a soft skill set when he returns.

A small sample strikeout rate breakout in 2022 at Triple-A failed to carry over for Bailey Falter, who now finds himself back in Triple-A after weak results, driven by an inability to generate whiffs. His fourseam velocity was down, while his slider’s SwStk% fell this year, after a pretty solid showing last year. If he was able to recapture the magic he enjoyed last year, with three pitches generating double digit SwStk% marks, there would be intrigue. But I’m not confident he’ll be able to do that, especially with a sub-91 MPH fastball.

Corbin Burnes’s SwStk% is just 11.8%, while his strikeout rate is down to just 21.5%?! What is going on with this world?! His pitch mix has mostly remained the same, but the velocity on four of his five pitches is down, including a nearly one mile per hour decline on his cutter. In just one start did he average 95.1 MPH with his cutter, the same mark he averaged all of last season with the pitch. Of course, he still sports four pitches with double digit SwStk%, which is quite impressive.

However, the marks are all lower than his career averages, which reminds us of how incredible he has been in recent years. For example, a 17% SwStk% on his slider is very good, but still significantly worse than his 26.9% career average, which is the elitest of the elite. I wouldn’t have expected a marginal drop in velocity would have such a dramatic effect on his whiff ability, but here we are. I’m not sure if I would target him in a trade, as it depends on the discount you would get compared to his draft day cost.

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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9 months ago

Gerrit Cole is also down 3.3% after last night’s start vs. Baltimore. From 14.3% last year to 11.0% this year