Masahiro Tanaka Might One Day Kill the Fastball

A few years ago there existed a fun little game to play, brought to my attention by Sam Miller, I think it was. The instructions were simple: Follow a Justin Masterson start, and see if he’d go the duration without ever throwing anything other than a fastball. Masterson would live and die by his sinker, and while he wasn’t the only fastball-heavy starter around, he would sometimes take things near the one-note extreme. Depending on your perspective, it was a testament either to his talent or to his limitations.

I don’t remember if Masterson ever did it. It wasn’t the kind of game you’d play for the memories. But these days, you could play a very similar, if opposite game. You can follow a Masahiro Tanaka start, and see if he goes the duration without ever throwing anything other than a non-fastball. The odds are presumably slim, because every new start brings 90-some chances, yet Tanaka is trending in a certain direction. You could just ask the Indians last night.

Any 1-0 game involves more than one hero. The Yankees wouldn’t have been able to avoid elimination in such a way were it not for Greg Bird. Aroldis Chapman, too, recorded five late and critical outs. But Tanaka was given next to zero margin for error, and he delivered with seven shutout innings, picking up seven whiffs against one of the best contact-hitting lineups anywhere around. Tanaka, of course, was paid what he was to deliver games just like this, but there was something extreme about Game 3, even by Tanaka’s own standards.

Every pitcher, in theory, begins with a fastball. That’s the pitch off of which every other pitch works. Tanaka doesn’t struggle to generate velocity — his own fastball is consistently around 92, give or take. That same fastball has been obliterated. Our leaderboards keep track of pitch-type run values, and one of the measurements is average value per 100 of the given pitch type. Out of every pitcher with at least 500 innings thrown since 2014, the only guy with a less effective fastball than Tanaka is Jered Weaver. Weaver, who, later in his career, attempted to explore the lower boundaries of employability. Weaver’s fastball was a running joke. Tanaka’s fastball wasn’t very much different.

And so Tanaka has simply thrown fewer and fewer fastballs.

Let’s pull back. That plot is able to compare Tanaka against himself, but it doesn’t offer much other context.

You might’ve heard during the Game 3 broadcast that, among starters, only R.A. Dickey threw a lower rate of fastballs this season than Tanaka did. One of the announcers said that Dickey basically doesn’t even count, since knuckleball pitchers are their own unique breed. But if you’re willing to over-simplify, why doesn’t Dickey throw many fastballs? His fastball isn’t good, and his other pitch is. Tanaka is a similar kind of non-fastball specialist. It’s been proven time and time again that his fastball isn’t very good at retiring major-league hitters. So he hardly let the Indians see any fastballs.

Over seven innings, Tanaka threw 92 pitches. According to Brooks Baseball, 15 of them were fastballs. That meant Tanaka had a fastball rate of 16%, which is — narrowly — his lowest-ever fastball rate in a single game. At the same time, Tanaka seemingly didn’t throw a single cutter. This is all based on outside classification, and it’s not coming from Tanaka himself, but, let’s take this for what it is. Brooks Baseball groups fastballs and cutters together as “hard” pitches. Tanaka, on Sunday, threw hard pitches 16% of the time. That’s easily his lowest rate ever. Tanaka threw nearly as many curveballs as fastballs, and he threw dozens of sliders and splitters.

The game’s first out came on a splitter.

Tanaka’s final strikeout came on a splitter.

In fact, all of Tanaka’s strikeouts came on a splitter. Yet, this wasn’t just a matter of two-strike fastball avoidance. Tanaka simply refused to give the Indians what they wanted. Tanaka faced 23 batters, and of his 23 first pitches, only six were fastballs. Tanaka, additionally, threw 18 pitches when he was behind in the count, and, out of those 18 pitches, only one was a fastball. This was something beyond just pitching backwards. This was leaning on secondary stuff almost entirely. And Tanaka did it, because his secondary stuff is his primary stuff. His fastball might be his true offspeed pitch.

This article came close to not being written, because the Indians came close to not losing. In the top of the sixth, Francisco Lindor just about drove a splitter out of the yard.

Yet we can’t go around giving credit for almosts. The home-run robbery wasn’t much of a home-run robbery. The contact quality was nothing exceptional. Francisco Lindor hit a fly ball. Aaron Judge caught it. The Indians never scored. Tanaka got his result, even if it made him sweat for a few seconds.

That ball was caught, and the Indians otherwise seldom threatened. Theirs is an able and disciplined lineup, but Tanaka is capable of turning hitters on their head, because the normal approach for so many guys is to step up looking for the fastball. You look for the fastball and try to adjust to something else. You can’t do that against Tanaka when he’s not throwing fastballs, because his other stuff is too good. His slider is too sharp, and his splitter is too well disguised. So hitters have to sit on something else, which they’re not so accustomed to doing. By no means is this to suggest that Tanaka is unhittable — he finished with an ERA closer to 5 than to 4 — but he succeeds in making hitters uncomfortable, because his approach is his own. If there’s a league-wide trend away from the fastball, in the direction of one’s better pitches, Tanaka’s in the vanguard. It’s not all Rich Hill and Lance McCullers.

One day, Masahiro Tanaka might go a whole start without ever throwing a fastball. It might happen because his slider and his splitter effectively are his fastballs. What is a fastball, after all, if not just a pitcher’s most trusted pitch? Fastballs are thrown frequently because they’re how pitchers best know to throw strikes and hit spots. Tanaka’s repertoire is his own burden and blessing.

Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.

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6 years ago

Tanaka gets the highest O-swing of anyone in baseball. Batters are constantly swinging over splitters that fall out of the bottom of the zone.

Isn’t part of the answer for the league to adjust back and swing less?

And yes, I realize that’s easier to do from my keyboard than from the batter’s box.

(I recall this being floated for Francisco Liriano as well, although I don’t know what came of it other than Liriano stopped being good, and instead of reverting back to interesting-bad he just became regular-bad).