Yu Darvish has been on a quite a run lately, but what’s behind the change in his fortune?
After signing him to a six-year, $126 million contract, the Chicago Cubs got eight starts, 40 innings and a 4.95 ERA out of Yu Darvish before a triceps injury sidelined him in 2018. A shoulder issue took him out of a rehab start in August, followed by an elbow issue that required minor surgery in September. All in all, Darvish seemed to be the latest example of the folly that is signing a 30-plus-year-old starting pitcher to a big contract.
Early this season, things weren’t any better for Darvish. Over his first 13 starts, he had a 4.88 ERA with a 6.0 BB/9 and a 10.6 K/9. The strikeout rate is fine, but that walk rate negates it. Over 12 starts since then, he has a 3.59 ERA with an 11.2 K/9 and a 0.9 BB/9.
Last Thursday night against the Philadelphia Phillies, Darvish had his fourth straight start with at least eight strikeouts and zero walks. Since the All-Star break (seven starts), he has a 2.36 ERA with a 12.2 K/9 and two walks over 42 innings (0.4 BB/9). Heading into the All-Star break, even with a few better outings mixed in, he had a 5.01 ERA, a 10.3 K/9 and a 4.5 BB/9.
So what’s behind Darvish’s resurgence?
Heading into his last outing against the Phillies, splitting his season into pre-June 10 and since over nearly the same amount of innings at that point, FanGraphs cited a nearly six percent boost in how many pitches Darvish is throwing in the heart of the strike zone (as determined by Statcast). That has yielded the aforementioned dramatic reduction in walks (14.9 percent walk rate before June 10, 2.7 percent walk rate in the 11 starts since then to that point), but also a slight uptick in home run rate (3.7 percent before June 10, 5.8 percent in the subsequent 11 starts). Remove allowing three home runs on the road against the Cincinnati Reds on Aug. 9, in the bandbox that is Great American Ballpark, and that home run rate easily evens out.
Darvish has allowed 15 home runs since June 10, but nine have been solo. So merely not putting extra guys on base has minimized the damage done by allowing a few extra home runs.
FanGraphs also showed that Darvish has traded throwing a pitch he has struggled to command, his slider, for throwing his cutter more. Compared to 2017, his last significant sample, he has thrown his cutter better in the shadow (or “the black”) of the strike zone and hitters are chasing it more often this year.
Darvish has a wide repertoire of pitches, and it’s notable he has increased his split-finger fastball usage in line with his ace-level run lately.
Overall this season, Darvish is throwing his splitter 7.6 percent of the time. Throwing it almost never from April-May skews that rate downward, But pushing over 10 percent in three August starts (nine times in 92 pitches against Philadelphia most recently) is to the high end and brings risk he’ll have a recurrence of arm issues.
Darvish will make his next start Wednesday night against the San Francisco Giants, who he faced on July 23 in the last outing he walked a batter. His recent run of elite command is not sustainable, but someone within the Cubs organization appears to have gotten some pitch usage data to Darvish. Credit to him for bringing it to the mound, and executing it as he has since a rough start to the season. Through a stretch when the bullpen and some other starters have struggled, the Cubs have gotten the kind of pitcher they paid for.