### Baseball News from Yesterday (April 21, 2018)

You probably have read that Brandon Belt set a MLB record with a 21-pitch at-bat yesterday. To get an idea of how extreme this AB was, here is a bar plot of the number of pitches for all the at-bats in the 2017 season with Belt’s record shown.

### Chase Utley’s HBP’s

The reader is probably not surprised to learn that Chase Utley has been one of my favorite players. He was a big part of the Phillies success ten years ago when they won the World Series in 2008 and appeared again in the Series in 2009. One of his attributes at the plate was his unwillingness to move away from the plate and so Utley tends to be hit by the pitch a good amount. In fact, Utley passed a milestone recently by getting hit for the 200th time in his career. MLB recently published an interesting article graphing all of the locations where he has been hit (the author calls it a “HBP Body Chart”). Anyway, this motivated me to explore Utley’s HBP’s over his career. Specifically, I’ll focus on several questions:

- How does Utley compare with other batters with respect to HBP?
- Are there any interesting patterns to his HBP rates over his career?
- On average, how many plate appearances are there between successive HBP’s?

### HBP Rates

We know that Utley has (at least) 200 HBP in his career, but how does that compare with other players? Since the number of HBP depends on the number of PA (plate appearances), it is better to explore the HBP Rate = HBP / PA. I focused on the players with at least 300 PA — below I graph the HBP rates of these “regulars” for each season from 2003 and 2016 and show Utley’s HBP rages by red dots. (By the way, in the process I spot a remarkable outlier — Brandon Guyer was hit 31 times in 345 PA in the 2016 season.)

We see that Utley was generally among the best in getting hit-by-pitch for most seasons during his career. His rates were especially high during the 2007 to 2012 period which were the best seasons of his career.

### A Graphical Representation of Utley’s HBP’s

Using the Retrosheet play-by-play data it is easy to find the actual PA’s where he had his HBP. Below I use a “rug-type” graph to show the individual PA (using vertical lines) of these events. The density of these lines appears dense during the 2007 to 2012 seasons when his HBP rates were the highest. (By the way, this type of graph of streaky data is done using the `plot_streak_data`

function in my `BayesTestStreak`

package.)

### Spacings and Utley’s HBP Rate Trajectory

Although this graph is somewhat helpful, I want to look closer. By use of the `find.spacings`

function in the `BayesTestStreak`

package I can find the gaps or spacings between successive hit-by-pitches. For example, in the 2005 season, Utley was hit 9 times and we record the actual PA on which he was hit. The spacings are

102 34 25 91 139 8 132 63 15 10

meaning, he had 102 “not HBP” before the first HBP, a gap of 34 “not HBP” before the second HBP, and so on. We can summarize these spacings by a median — here the median is 48.5 which means that a typical gap between HBP’s was 48.5 PA. Below I graph his median HBP spacing against season. In his best HBP seasons, Utley generally was being hit about every 20th PA. There is an interesting large outlier in 2013 — I wondered what happened in this season to drop his HBP rate?

### Interesting Takeaways and Looking Ahead:

- Obviously Chase Utley was one of the leading HBP players during his MLB tenure. There is an ability aspect to getting hit by the pitch — it certainly is not just due to the pitcher — and Utley did not appear to be afraid of being hit.
- It is interesting that Utley’s career trajectory of HBP matches his career trajectory of his success as a hitter. His best HBP rate seasons corresponded to his best hitting seasons using any reasonable metric.
- By looking at the spacings you get a nice interpretation of his HBP rate in terms of the gaps between successive HBP events.
- It would be interesting to do a more thorough study of HBP rates. How have these HBP rates changed over the history of baseball? What types of hitters tend to have high or low HBP rates? Do hitting trajectories have any similarity with HBP rate trajectories?
- Chase Utley has had some interesting streaks and slumps during his career. In an earlier post I explored a hitting slump of Utley during the 2015 season.