From Godhood to Earth: Analyzing Josh Bell's Second-Half Collapse

Josh Bell, who had a breakout year for the Pirates, was once considered a strong contender for the National League MVP. Before the All-Star break, he had already posted 27 home runs, 84 RBIs, and a slash line of .302/.376/.648. In May this year, Fangraphs writer Ben Clemens penned an article discussing his success: Josh Bell, Now With Power. Another article from Sports Vision: The New Pirate King! The Secret to Josh Bell’s Ascent as a Top Slugger, also analyzed Josh Bell’s transformation from multiple angles.

Both articles commonly pointed out that Josh Bell’s success this year was due to a change in his batting stance. Before this year, Josh Bell’s batting stance was described as: inconsistent footwork. Let’s look at how inconsistent he was in 2018.

Wide Stance

Don’t doubt that this is the same person…

The footwork in the second image is slightly altered.

Ben Clemens noted that this year, Josh Bell found a consistent stance and footwork, which allowed his latent power-hitting ability to explode, turning him into this year’s monster.

However, after the All-Star break, his performance was like night and day. In 19 games and 75 plate appearances post-All-Star break, he didn’t hit a single home run, and his slash line during this period dropped to just .188/.307/.250.

So, is Josh Bell’s decline in performance due to his fixed batting stance falling apart again? It’s certainly possible, but I haven’t seen enough evidence in game footage to confirm this. Therefore, besides offering the explanation of a shifting batting stance, I’d like to share some other interesting observations with you.

Infield Fly Ball Machine?

The first observation is that after the All-Star break, Josh Bell started hitting an excessive number of infield fly balls. Before the All-Star break, Josh Bell’s infield fly ball rate (calculated as: number of infield fly balls / total number of fly balls) was only 2.1%. However, after the All-Star break, it surged to 16.7%, significantly higher than the league average.

Furthermore, a closer analysis of Josh Bell’s data as a right-handed and left-handed batter reveals that his infield fly ball rate as a right-handed batter increased most significantly. In the first half of the season, when batting right-handed, he didn’t hit a single infield fly ball. But in the second half, up to the time of writing, he hit 3 infield fly balls in just 27 plate appearances. This led me to wonder if it might be related to pitchers’ pitching strategies.

Although the sample size is still small, I noticed that in the second half of the season, when Josh Bell batted right-handed, fastball-type pitches (four-seam, sinker, cutter) were consistently thrown high and inside; while non-fastball pitches tended to be thrown high and outside. This change might have significantly impacted Josh Bell’s quality of contact, even causing him to start hitting many infield fly balls.

Changes in Fastball Pitch Locations Between First and Second Half

Changes in Non-Fastball Pitch Locations Between First and Second Half

Shift Strategy Changes?

Here, we are emphasizing infield shifts. First, let’s briefly introduce two different types of infield shifts.

Three or More Infielders on the Same Side of Second Base

This is the most common form of shift. Because the infielders move a greater distance, for convenience, this article will refer to it as a “major shift”. If you’re not familiar with the term, just take a look at the shift diagram below!

Major Shift Example

Strategic Shift

The official website currently defines “strategic shift” as all shift forms that are not “major shifts”. Common strategic shifts include the second baseman moving to the outfield grass in right field, the shortstop shifting towards second base, etc. In contrast to major shifts, we will refer to strategic shifts as “minor shifts” in the following discussion.

Minor Shift Example

Let’s get back to Josh Bell! Initially, Josh Bell wasn’t a player who was often shifted against. Even in recent years, as teams found that shifting against Josh Bell had some effect, the frequency of shifts against him increased. However, the league-wide shift rate has been rising annually, and Josh Bell’s shift rate relative to the entire league is still only about average. (Shifting against Josh Bell does have a considerable impact on his batting performance; those interested can look up the data, which won’t be listed here.)

So, did Josh Bell’s shift rate increase significantly in the second half? The answer is no.

Considering both major and minor shifts, Josh Bell’s shift rate (number of shifts / plate appearances) did not change significantly between the first and second halves this year. The first half saw a 42% shift rate, while the second half was 48%, which is not enough to convince me of a huge difference between Josh Bell’s performance in the two halves.

So what exactly went wrong? The problem isn’t solely with the shift rate, but rather with the proportion of major shifts relative to minor shifts.

Throughout Josh Bell’s career, the number of major shifts has almost always been much lower than minor shifts. We can directly look at the table below:

What about this year?

Even though the number of major shifts already started to exceed minor shifts in the first half of this year, the significant increase in the proportion of major shifts used against Josh Bell truly began after the All-Star break. We can look at my monthly statistics chart:

If the changes mentioned above aren’t convincing enough, we can also look at advanced offensive statistics like wOBA. wOBA, or weighted on-base average, is an excellent advanced metric for evaluating batting performance. We will find a clear difference in wOBA between major and minor shifts:

Therefore, the change in shift strategy by opposing teams after the All-Star break—beginning to heavily utilize major shifts and reduce the number of minor shifts—may have indirectly or directly impacted Josh Bell’s batting performance.

Conclusion

Josh Bell’s second-half regression is truly surprising. The author presents observations from Josh Bell’s data here, hoping to explain some of the reasons for his decline.

In addition to a potentially unexplained change in batting stance that might have led to Josh Bell’s performance dip, changes in pitch locations for various pitch types preventing him from making solid contact, and different shift strategies between the first and second halves could all be contributing factors to Josh Bell’s batting performance.

What’s remarkable is that even with such a poor second-half performance, he still temporarily holds the RBI lead at the time of writing, which shows just how incredible his first-half performance truly was. With nearly two months left in the second half, let’s see if this new-generation slugger can regain his formidable power!

Data Sources:

1. MLB Official Website
2. MLB Savant
3. Ben Clemens. (2019). Josh Bell, Now With Power. Fangraphs. https://blogs.fangraphs.com/josh-bell-now-with-power/
4. Fangraphs

Image Source: Pirates Official Website Image Gallery PC: Jason Miller/Getty Images

Cover Image Source: Pirates Official Website Image Gallery PC: Rob Tringali/MLB Photos