Even if you didn’t remember the exact point at which Yu Darvish started throwing a knuckle-curve last season, you could spot it easily by looking at game logs. If you pull up FanGraphs, you’ll note that his curveball percentage spiked to 16.9% on August 21 in a home start against the Giants. Baseball Savant will show you the same thing, along with a whiff percentage that jumped to around 45% after having been almost nil in 25 previous starts.
Yu Darvish added a knuckle-curve to his repertoire late last season.
When he did, his K/9 was 13.84 pic.twitter.com/ORMjfZo2Y5
— Marquee Sports Network (@WatchMarquee) May 19, 2020
Darvish posted a 13.84 K/9 mark over his final six starts of the season, good for an absurd 12.2 K/BB ratio when factoring his 1.13 BB/9 rate. Prior to the addition of the new curveball, which he said in September felt more like the hard curve he’d been forced to abandon following elbow reconstruction, Darvish had been at a mere 10.88 K/9 with a 3.29 K/BB ratio.