Tanner Roark Is Mixing It Up

When I talked to Tanner Roark back in 2014, he was in the middle of his breakout season and made sure to explain all the adjustments that led to that excellent year. But, even then, he gave us clues about his second act and what he might do in the future. And though the overall results have been uneven at times, it’s that kind of forward-thinking that has kept him productive. If he stays on the mound long enough in tonight’s Game 5, we’ll see some of those secondary adjustments in action.

Going to the two-seamer, improving his changeup and curve, putting an emphasis on strike one: that was all part of his first round of alterations. It allowed Roark to work as a starter for the Nationals after having served as a more fungible reliever with the Rangers.

But Roark’s sinker, even if it’s better than his four-seamer, is more of an average pitch than a standout one. In terms of sink (one inch off his fastball), fade (eight inches), velocity (93 mph), whiffs (5%), and grounders (60%), it doesn’t stand out a ton compared to the sink (three inches off the average fastball), fade (eight inches), velocity (92 mph), whiffs (6%), and grounders (51%) of an average two-seamer.

So if it was Roark’s intention to stick around, he was always going to have to address his other pitches. He gave a preview back in 2014 when we talked:

For the slider, the work is situational. Roark is working to find ways to use the pitch against lefties. “I’ve just got to bury it in the back foot,” for the most part, but he’s also been trying to work on going front door to lefties. He wants them to “give up on it on the outside corner.” Adding those two sliders is important — “The scouting report says he only throws these three pitches against right-handers and these three against lefties. I have four pitches for a reason, so I have to use all four,” Roark said.

Consider the goal accomplished — to an extent, at least. First, let’s look at his slider usage against lefties. It’s doubled in the last two years relative to his first two years. But when he first tried to use the slider against southpaws — which is frequently difficult for right-handers because the ball breaks right into the left-handers’ hitting zone — he was predictable. All back foot.

Now that he’s throwing them more often, though, he’s also mixing up the location. He back-foots the pitch, yes, but he also throws it in on their hands like a cutter and also tries to hit the outside corner so they give up on it.

Against righties, the transformation has been about the changeup mostly and the curve to a lesser degree. He used to be almost a two-pitch pitcher against righties. Now he’s really become less predictable.

Tanner Roark Pitch Selection vs Righties
Pitch Type 2013-2015 2016-2017
Four-Seam 13% 19%
Sinker 51% 40%
Change 1% 5%
Slider 30% 25%
Curve 5% 9%

Maybe the differences don’t appear as stark when presented this way, but let’s try another. By changing his pitch selection over the last two years, Roark has replaced 286 sinkers and sliders with curves and changeups. This is what the conversion looks like in graph form.

When you see it that way, it clicks. Step one, to get into this league, was to figure out the fastball. Step two, to stay in this league, was to become less predictable in all situations. Step three, it seems, is do this all in a big spot for his team.

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With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.

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