Tanaka’s success depends heavily on his slider and splitter. The curve is just a “show me” pitch just barely cracking 3% similar to 2018 at 3.8%. Tanaka can certainly throw it for strikes (56.2% zone rate) but it has shown pretty much zero bat missing returning an invisible 2.3% swinging K rate.
At his best, Tanaka’s fastball will take a back seat and let his slider and splitter do the heavy lifting. Its easy to see why. The past two seasons the Tanaka fastball, which averages just about 91.5 mph, has been man handled by opposing bats allowing an xwOBA of just about .400. That’s not what you want.
Tanaka threw his cutter just 45 times this past season and mostly to RHB (39/45). Tanaka can throw it for strikes (54.4% zone rate) but its not a bat missing pitch returning a thoroughly boring 4.4% swinging K rate. It also was hit hard by to the tune of a .374 xwOBA. There’s just not much to see here.
The wheels started to fall off for Tanaka in 2019 mainly due to a lack of secondary stuff to back up his slider. The spilt-finger was the worst culprit. A drop in SwStr% from 22.0% in 2018 to just 11.2% in 2019 was further shadowed by an ugly 27.3% HR/FB ratio. All this adds to the question of what the Yankees should do with Tanaka as he enters his final year under contract.
With his splitter’s struggles this year, Tanaka found himself relying a little more heavily on the slider this past season throwing it at a career-high 36.3%. Tanaka had no problem at all throwing it for strikes this past year as it notched a stellar 46.7% zone rate. It also induced a 41.4% chase rate and 15.1% swinging K rate (33.7% whiffs). Tanaka’s slider was a money pitch this past season and it remains an integral part of his arsenal.
Tanaka throws his slider just about a third of the time, and perhaps he should use it more. It borders on being an elite pitch with a 17% career swinging-strike rate and a 1.7 pVal/C. Hitters last year had trouble making contact with the pitch, which sports a 0.19 BB/K rate.
Tanaka utilizes his splitter to complement his nasty slider. The pitch, much like his slider, has an elite swinging-strike rate of 22%, and Tanaka is able to keep the ball on the ground when he throws his splitter, which has a career 65% grounder rate.
One of the weaker pitches he throws, Tanaka’s four-seamer is at best a bad offering. Hitters simply mash against it, which Tanaka still throws about a quarter of the time. Perhaps he should reel that back a bit next year and rely more on his splitter rather than a pitch that allowed 27 homers in 433 plate appearacnes.
Tanaka limited the use of his sinker last year after employing it as a secondary pitch every season prior. That’s good for him, because his sinker was weak enough to be valued at -2.9 pVal/C in 2018.
Tanaka’s curve was elite as recently as 2017, a year in which opposing batters only hit .161 against it. However, last season he lost movement on the pitch, which allowed batters to tee up against it. He allowed a .500/.500/.900 triple slash over the 10 plate appearances he threw the pitch in last season.
Thrown only 3% of the time, Tanaka’s cutter is pathetic. In just 28 plate appearances last season he logged a measly one strikeout while giving up four home runs. This is nothing new to Tanaka. In 2017, he also gave up four long balls in only 14 more plate appearances. Going forward, Tanaka might be better off eliminating this pitch.