Shelby Miller: Fixed?

There’s a sort of check list you can go to when a pitcher’s performance changes. You run down the possible reasons, and if there’s no box checked, you shrug and figure a few bounces have gone differently and that was all that happened.

So what do you do when a pitcher has a breakout performance, then suffers a setback and then looks like he’s re-found what he’s lost? Especially when that pitcher doesn’t have any obvious checkmarks on the checklist? What do you say about Shelby Miller’s up-and-down year so far?

Before I talk to any pitcher, I sketch out something like the following table. So that checklist is literal in my case.

For this, I’d want to zero in on the curveball, which is seemingly less effective this year according to Brooks Baseball’s numbers. The fastball hasn’t seen too much of a difference in velocity, the change isn’t a primary pitch for him and wasn’t ever that great and the cutter has been better this year.

But check out the curveball’s vital stats on a checklist table of another sort.

Does that paint the picture of a radically different pitch? For every mile per hour it lost in velocity, the curve gained a bit of vertical and horizontal movement. Now more of a roundhouse curve than it’s ever been, Miller’s yakker should (theoretically) have the reverse platoon splits to marry well with his improving cutter.

So why the downturn in effectiveness from the curve? Not only are his whiffs down by almost half, his ground-ball rate on the pitch is down to 30% — from 43% last year. It reads like a below-average pitch on paper. And yet it still looks like this.

A year after he put up 173 innings with a 3.06 ERA backed by a 3.67 FIP, Miller responded with a 3.74 ERA backed by a 4.54 FIP. Could be easy enough, in the light of only small changes in stuff and no traditional luck estimators out of whack — batting average on balls in play, strand rate and home runs per fly ball all favor the pitcher or are league average in both years — to say this year tells us more about his true talent than last year. That’s what the projections would say anyway, as they weight recent performance slightly heavier than past performance.

But how about his *most* recent performances? Since the beginning of August, Miller’s ERA is less than three. He’s been walking fewer batters (2.6 per nine, in line with his first two years). And other than a slight increase in curveball usage (up over 20%), most of his stuff has been the same.

Except maybe one thing: Check out his heatmaps for early in the season, on the left, and for August and September, on the right.

We’ve written a lot here about how the high fastball can be effective, and how there’s recent evidence hitters are having a harder time with high fastballs. Throwing more high fastballs might be leading to the higher fastball whiff percentages — Miller is back over 10% whiffs on the fastball for the past two months for the first time this season. At least the fastball is back to glory. After all, Miller’s late-season heat map looks more like his 2013 heat map than his early-season one:

As a curveball pitcher, it could be important to mask the pitch with a high fastball, and that could be how different fastball location has made his seemingly similar curve less effective this year. But if this is true, it hasn’t yet taken root. Miller’s curve got around 5% whiffs in August and September. Perhaps he hasn’t completely fixed what was once broken, but the curve doesn’t seem to be hanging as much now.

It’s true that in small samples, the renewed dedication to the high fastball could just be due to the particular matchups that the Cardinals saw in the late season. His past two games have seen the highest average vertical location for his fastball in his career. Since we’re previewing his start against the Giants tonight, though, this adjustment seems important.

And now that we’ve gone through most of my preparation for the interview, it’s time to go to the player. In a press conference. With one question.

Question: You really did well late in the season, but it didn’t seem like much changed about your arsenal in terms of the pitches you threw and their velocity and movement. Did you maybe change something about the location, maybe throw the fastball high in the zone or anything like that?

Shelby Miller: You know no, not for the most part. We always have kind of a game plan going into it and I’ve always been a guy who — don’t shake the catcher too much. Following guys that have been around for a while and know these hitters a little better than I do, that’s what I go with. When I feel comfortable with a certain approach, I’ll go with a certain pitch. But for the most part, these guys do an extremely good job calling games and make my job a lot easier. But for the most part, same pitches, same scenarios, not really changing up anything pitch-wise.

Thanks to user fanforever on gatewayredbirds.com for the GIF.