Remember When Yu Darvish Started Throwing a Knuckle-Curve? That Was Fun

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.

“I used to throw the hard curve, but that was before Tommy John,” Darvish told reporters after striking out 14 Padres, seven on the curveball. “After that, I struggle with that pitch, my best pitch. Kimbrel taught me the knuckle-curve, and I feel that can be my best pitch.”

The knuckle-curve was thrown slightly harder (78 mph vs 76.7) and with just a little more spin than his more traditional grip, but it’s not the stuff alone that suddenly made Darvish more effective down the stretch. Perhaps even more important was the renewed confidence to throw his curveball as a put-away pitch rather than just a get-me-over offering early in counts.

To wit, he threw that breaking pitch a total of 92 times over his final six starts (15.33 per start) after going to it just 105 times over his first 25 starts (4.2 per). The increased frequency and efficacy led to 21 whiffs on the curve in that more recent sample as compared to just nine across the earlier one. Darvish generated a swing and miss in only seven different games across his first 25, twice registering two whiffs in a game.

For the sake of comparison, he got five whiffs on the curve the first time he incorporated the knuckle wrinkle in late August. Adding to the ludicrousity — I don’t care about that red line — of the whole situation is the fact that Darvish had just started throwing the new pitch that day against the Giants. Not just throwing it in games, but throwing it at all. Maybe he experimented in a side session a day or two before, but the apocryphal tale holds that he first tried it out during his pregame bullpen and was given the green light by Joe Maddon to cut it loose.

None of this is in any way revelatory, of course, but I saw that tweet from Marquee and it really had me missing the stories that come out of the baseball season. Man, I can’t wait to get the chance to see Darvish pitching again. Or to see anyone pitching again, for that matter. I’d even settle for Steve Trachsel, though it appears the weather has plenty of its own rain delays in store over the next two weeks.