Going into the season, I was a little worried about Shields' changeup SwStr%, as it had declined every year since 2010 and wasn't great last year (16.3%). The changeup has always been his signature pitch and he wasn't able to lean on it as much.
But this year, changeup SwStr% has jumped to a career high and Shields is also throwing a knockout curve for the first time and getting great fastball whiffs too. All of his pitches are suddenly much better; he's generating an absurd 14.0% SwStr% overall and still throwing a ton of strikes and has an average-ish batted ball distribution. It's a beautiful thing.