On the surface, his 3.81 ERA is respectable (league average is 4.57 this season). He’s thrown 111 innings, and he’s arguably been the most important pitcher on the Yankees’ staff. Yes, German has been better on a rate basis, but Tanaka has had nearly 30 more innings of above average production, which isn’t insignificant. Tanaka’s WAR sits at 2.1 and he’s on track to cross the 3 WAR threshold for just the second time in his career. However, we’ve seen a different Tanaka this season, so let’s examine what he has been doing differently.
Limiting Home Runs:
Ever since he came to the big leagues, Tanaka has had problems keeping the ball in the ballpark. Hell, he gave up a home run to the first batter he faced (former Yankee Melky Cabrera). While otherwise being solid for the Yankees, this nagging issue continued for a while and reached untenable levels in the summer of 2017. His 21.2% home run rate, percentage of fly-balls that left the ballpark, was worst in the league that year. Last year, he reduced that mark to 17.7%, and this year it’s down to 16.2%. See below for a graphical representation:
Tanaka is always going to give up the occasional dinger. He lives and dies with his off-speed stuff, and that comes with the territory, but he’s done a better job pitching backwards the last few years and keeping hitters more off balance. His “barrel rate” has also decreased over the last 3 seasons, 8.6% in 2017, 7.1% in 2018, and 6.3% this season.
Tanaka has seen his strikeout rate take a hit this year (7.7k/9, career 8.59 k/9) but his walk numbers have been right around his average (2.03 bb/9, career 1.78 bb/9). The reduced strikeout rate has led to some below average peripherals for him (4.34 FIP), but perhaps he can clean some of that up. Considering he has been without his signature splitter this season, these numbers could be a lot worse. See below for how Tanaka has changed his pitch selection recently:
To say Tanaka has been missing his best pitch this season would be an understatement. As of now, fangraphs says his splitter has been worth –8.7 runs this season. This would be the first season for him in which that pitch produced a negative value. He is making up for the loss of his splitter with his slider, which has been worth +14.4 runs. His previous high with that pitch was set last season at +17.9 runs.
There is some speculation that the new baseballs are a factor for Tanaka. He spoke with NJ.com interpreter Shingo Horie last week and had this to say: “Probably the right word to say is, it just doesn’t feel right.” “Feels like the ball is a little bit harder and it feels like the seams are a little bit lower,” Tanaka said.
If the ball that MLB is using this year has lower seams, it would certainly affect a pitch like a splitter. Tanaka being able to remain effective is a testament to his tenacity as a starter.