In the final game of the 2013 Japan Series (Japan's equivalent of the World Series), Masahiro Tanaka famously came on in relief to close the game for his Tohoku Rakuten Golden Eagles. In that appearance, he did something that would seem unthinkable now: almost all of his pitches were fastballs. Sitting at 93-94 mph, he gassed opposing hitters away to clinch the championship, riding off into the sunset to go join the New York Yankees.
Since coming to the United States, Tanaka's fastball has been more of an Achilles' heel. As a result, he has become extremely reliant upon his splitter and slider, throwing either a four-seam fastball or sinker just 32% of the time last season. Starts like yesterday show why this kind of game plan might not be very sustainable.
Facing the Blue Jays, Tanaka managed to hold Toronto's high-powered offense to two runs in five innings. But it occasionally looked like Nathan Eovaldi was on the mound instead, as he finished the fifth with 92 pitches. Because his slider command was off, he was often unable to put hitters away, walking hitters even after getting ahead to an 0-2 count.
Even if reaching his 2014 level is impossible, the Yankees would be more than happy if Tanaka could regain his status as an innings eater. In order to do so, he will have to find a way to use his fastball and sinker more effectively.
During the offseason, I wrote about how the long stride in Tanaka's delivery may be leading to his home run problems. Because he reaches so far down the pitcher's mound, the 6'3" Tanaka is pitching like someone who is much shorter, reducing the downhill plane on his pitches. Interestingly, San Francisco Giants pitcher Johnny Cueto happens to be a front of the rotation starter, at just 5'11". What's more, he happens to be very particular about how he uses his fastball.
While Cueto has been known as a front of the rotation starter since 2011, he has definitely encountered his fair share of struggles as a pitcher. In 2009, a 23-year-old Cueto had a 4.41 ERA in 30 starts for the Cincinnati Reds. Here is how he used his fastball in 2009, versus last season:
Since the 2009 season, Cueto has made an effort to elevate his fastball, while throwing it away against righties and inside to lefties. The results have definitely been noticeable:
|Hitters vs. Cueto Fastball||BAA||SLG||Whiff/Swing%|
There are a few reasons to believe that a similar tactic could work for Masahiro Tanaka. First, elevating his fastball might address the issue of a lack of downward plane on his pitches. Theoretically, his release point should not matter as much on pitches up in the zone, since they aren't meant to have as much downhill action in the first place.
While pitching up in the zone is usually associated with flyball pitchers, the tradeoff may be worth it. With the Reds, Cueto made roughly half of his appearances in the extremely hitter-friendly Great American Ballpark. His success in a power hitter's paradise suggests that the same thing can be done at Yankee Stadium.
It is also possible that continuously changing the eye level of opposing hitters improved the quality of Cueto's secondary pitches. Possibly through a pitcher's version of Darwinism, Masahiro Tanaka's ability to command his slider and splitter is pretty solid. If he elevates his fastball more often, he can focus on keeping his secondary stuff down in the zone.
As the season progresses, Masahiro Tanaka should consider elevating his fastball in order to successfully reintegrate the pitch into his game plan. Depending on a pitch that yielded an opposing OPS of .982 in 2015 is not a very sustainable strategy. But as his performance this season has shown, having such a drastic reliance upon his secondary pitches might not be sustainable either. If Tanaka can successfully elevate his fastball, he might be able to elevate his overall performance as well.
Data is courtesy of Fangraphs and Brooks Baseball. Heatmaps are from Baseball Savant.