Analyzing Danny Duffy Part 2: The Scouting

Last week I decided that I wanted to go back and figure out what was wrong with Danny Duffy in 2018. If the Royals even want to be semi-competitive in 2019, they have to get Danny Duffy back on track. I hypothesized that, given the results just weren’t there for Duffy in 2018, something must’ve been wrong. Mechanics, injury, what ever. Surely the raw data would help tell the story.

Of course, it was just the opposite. When going back and looking at the data, I found that Danny Duffy actually threw the baseball better in 2018 than he did in 2017. To be clear (for those of you losers who don’t go back and read the first article), this has nothing to do with actually pitching. The data I looked at was velocity and spin rate, which was up on all of Duffy’s pitches. The ball was physically coming out of his hand better, obviously he was not as good of a pitcher.

One of the first things we identified in article one was that Duffy’s walks were up significantly in 2018. If you just look at Duffy’s heat map from 2018 and 2017, you would not know which of the maps resulted in more walks.

Pretty much the same heat map. The top one was 2017, but the general location of Duffy’s pitches doesn’t really help us. But uhh, now I am going to show you the heat maps on Danny Duffy’s breaking balls from 2017 and 2018.

I am pretty confident that any one still reading this article doesn’t need me to explain those images to them. That is really, REALLY bad. You simply can not leave breaking balls that high and expect to have good results. Let’s take a look at the heat maps for his changeup, just in good practice.

Nothing glaring here. If anything, Duffy’s changeup was maybe off the plate more in 2018, which isn’t bad in isolation. Let’s do fastballs now.

Again, same basic map. Which leads us with one major difference in locations between 2017 and 2018: the breaking ball.

One of the biggest issues with Duffy’s breaking ball location in 2018 is that it impedes on his ability to “tunnel” his pitches. Tunneling is the act of throwing two different pitches in the same “tunnel” so that they look the same at first, and then wind up in different places. If Duffy’s breaking pitches are finishing as high or nearly as high as his fastballs are finishing, then they have to be starting higher. This means that they can’t be coming out of the same tunnel as the fastball. This gives hitters more time (which isn’t much but more is more) to identify a breaking ball and either crush it, or not swing.

* The next part of this article may get a bit confusing. I’m going to ask you to keep scrolling though and find the end, instead of just opting for that darned back button. *

I believe that, despite the raw PITCHf/x data telling us otherwise, that injuries played a role in Duffy’s 2018 season. He had an operation to remove a loose body in his pitching elbow this past offseason which undoubtedly disrupted his off-sesason training programs. The surgery set Duffy back six weeks, but those six weeks can be huge for a pitcher’s training regimen. Maybe Duffy wasn’t physically injured during the 2018 season, but I guarantee you there were lingering effects from a sabotaged off-season. Here’s why.

The following graph represents the horizontal release point with which Danny Duffy released the baseball over the years.

Obvious trend, obvious trend, obvious trend...BOOM. Reversal. Now, really, all Duffy did was return to the same basic release point that he had back in 2016. But why the sudden change in trend?

1. Duffy and the coaching staff identified the trend and decided to be proactive about it.
2. The decreased use in Duffy’s slider and increase in his curveball have created a change in the overall data.
3. Duffy felt more comfortable with a different release point which could be due to prior injury.

It’s impossible to know for sure why this trend occurred during Duffy’s 2018 season, all we need to note is that it did in fact occur. When watching some video of Duffy from 2014, 2017, and 2018, there are some things that I notice that are different, but would be really difficult to explain without a video and a podcast (which isn’t impossible I’m just not sure how to do that at the moment).

To Conclude

Here’s what we know based on the data and some mild scouting:

1. The baseball was physically coming out of Danny Duffy’s hand better in 2018 than in 2017
2. Danny Duffy was not nearly as good of a pitcher in 2018 as he was in 2017
3. Danny Duffy had an operation in between the 2017 and 2018 seasons
4. Danny Duffy’s breaking ball location was abysmal in 2018
5. Danny Duffy threw far more curveballs in 2018 than in 2017
6. Danny Duffy threw less sliders in 2018 than in 2017
7. The general location of all of Duffy’s pitches didn’t change much in 2018
8. After years of a consistent trend regarding Duffy’s horizontal release point, Duffy had a sudden reversal of said trend in 2018

I make no claims of being able to identify what caused Duffy to be worse in 2018 than in 2017. As a former pitcher that has had loose bodies removed from their elbow before, I can tell you that that is no small operation. It may seem minor, but imagine if all of a sudden your arm moved in ways that were painful just months before.

My Theory

After looking at the data, I wonder if Danny Duffy wasn’t TOO healthy for most of 2018. The stuff was fantastic. He was throwing the ball hard and spinning it fast. All of a sudden he found his preferred release point again. It was just too much change all at once. Going back to an old release point combined with new found strength may have been too much of an adjustment for Duffy to make in one (half) off-season. Given a full season and now a full off-season, I wonder if Duffy won’t be really good again in 2019. Again, the stuff is there, getting a feel for locating his breaking balls may be the biggest gap between good Duffy and bad Duffy.