Hanging Pitches

Wade Miley hasn’t been a fantasy-relevant pitcher this season with his 5.36 ERA, but his performance on Tuesday night against the White Sox piqued my interest nonetheless. He wasn’t particularly good in the start, allowing three runs with just four strikeouts and three walks over 6.1 innings. However, Miley was just two pitches away from preventing the White Sox from scoring at all.

In the top of the second with the game scoreless, Miley hung a curveball that Brett Lawrie took deep into left center field.

Then, in the top of the seventh with the game again tied, now at 1-1, Miley hung another curveball that Melky Cabrera deposited into bullpen in left field for another home run.

Miley recognized the damage of those two hung pitches in his postgame interview: “It was really two mistakes. Both of them got hit in the seats. Two hanging curveballs, just got to get those pitches down. For the most part I felt like I threw the ball well. That’s it, two mistakes.”

It’s not a secret that hung curveballs tend to get hit hard, but it occurred to me that I had never seen or performed any research on the subject. Based on the general observations I have had of baseball, I decided to look at three types of offspeed pitches—curveballs, changeups, and sliders—to see if I could discover an effect of hanging pitches in batter production.

The greater trick was isolating what pitch locations should be considered “hanging”. To try to keep things relatively simple, I opted to focus on pitches that were thrown in the strike zone that hitters swung and made fair ball contact against. From there, I split the strike zone into three vertical zones as one would typically see in a strike zone heatmap. I labeled pitches in the bottom zone as commanded and the pitches in the middle zone as hung. I threw out pitches in the top third of the zone because, since the pitch types I was focused on were breaking pitches, I was concerned that those high pitches might be intentionally or unintentionally effective since many would start high out of the zone and then fall in.

Looking at the wOBA splits on those contacted balls since the start of 2015 for all pitchers, it is pretty clear that hanging pitches are bad news for pitchers. However, the different pitch types show pretty dramatic differences in terms of damage. Changeups show by far the largest difference. Hung changeups have the highest wOBA on contact of .437 while commanded changeups have the lowest wOBA on contact of .361. Curveballs fall in the middle with a 38-point difference, and sliders were nearly unaffected with just a 14-point spread.

I didn’t list it in the table, but fastballs showed a similar split to sliders.

Now confident that I had a working classification of hanging pitches, I shifted my view to individual pitchers. Here are the qualified starters in 2016 with the highest wOBA on contact allowed on their specific breaking pitches over the last two seasons. I limited the leaderboard to pitches each starter has thrown 25 or more times over those two years.

Miley makes an appearance in the top 20, but he does so with his changeup rather than his curveball. The .377 wOBA on contact Miley has allowed on his hung curveballs is actually the best of his three offspeed pitches. Prior to that Tuesday start, Miley’s wOBA on hung curveballs was a miniscule .254.

I didn’t undertake this research with a strong hypothesis on what the results might represent, but in seeing them, I started to wonder whether they might function as a proxy for the quality of the pitch. Obviously, location is hugely important for every pitch, but I would think that pitchers with better “action”—be that more break or just break that is harder to pick up for the batter—would be more likely to get away with their mistakes up in the zone. Since this study focused on qualified starters in 2016, then there is a baseline of successfulness inherent in the sample. However, among those qualifiers, both Martin Perez and Robbie Ray are on the low end of “stuff”, at least based on my perceptions of them.

Conversely, take one guess as to which pitcher has the pitch with the lowest wOBA allowed on contact when he hangs it.

Once again, Clayton Kershaw defies all logic. On his 43 hanging curveballs he has thrown in the zone and that have been contacted since 2015, batters have just a .103 wOBA. Specifically, he has allowed 5 singles compared to 23 groundouts, 13 flyouts, and 2 lineouts.

A few weeks ago, Eno Sarris wrote an article for ESPN Insider (subscription required) that identified the best pitches thrown by starters in baseball based on their swinging strike rates and groundball rates, and it was Kershaw’s slider and not his curveball that made the top list. But the thing that really struck me in watching all of Kershaw’s hung curveballs was how rarely hitters seemed in balance and making good swings on the ball. One benefit Kershaw has with all of his pitches is the fact that his entire repertoire is so good, and that makes each of his individual pitches difficult to look for and identify. And, of course since we’re talking about Kershaw, he is also on the leaderboard with his slider having allowed a .245 wOBA on contacted balls when he hangs them.

Corey Kluber’s curveball was on Eno’s top list, as well, and is fourth on this one. No one else made both lists, but many of the pitches that showed up here are at the top of the leaderboards of pitch type run values per 100 thrown pitches. Kershaw, Jacob deGrom, Masahiro Tanaka, Francisco Liriano, and Chris Archer all make the top 20 in slider run value per 100 pitches and are on this leaderboard. Kluber and Kershaw are in the top 20 for curveballs, and Zack Greinke, Marco Estrada, and Edinson Volquez are for changeups.

I think the similarity between pitcher wOBA on contact allowed and the pitch type linear weights of those pitchers suggests that the quality of pitches influences batters’ success against them when they are hung. As such, I’m going to refrain from making any claims about which pitchers have been the most and least fortunate on their hanging pitches—which was where I originally thought this post was going for fantasy purposes.