Does the MLB Home Run Derby affect second half performance?

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By Clare McMullen

As the halfway mark of the MLB season rolls around, baseball and sports fans alike look forward each year to the ever-entertaining evening that is the Home Run Derby. Since its inception at the 1985 MLB Allstar Game in Minneapolis, Minnesota, the event’s format has continuously evolved.

However, the goal remains the same; hit the most home runs.

The Home Run Derby has arguably become more popular than the All-Star game itself. Fans flock to see the league’s best power hitters outslug each other in a display of incredible skill and immense power. Despite the widespread celebration of the event, some critics bring up the so-called “Curse of the Home Run Derby” every year. Some argue the Derby is detrimental to participants, causing fatigue and injury that negatively impacts the player’s second-half production. My goal is to determine if there is any truth to this myth or if we can simply enjoy watching our favourite players participate without worry.

Data Collection

I began by compiling a list of every Home Run Derby participant since 2010. From this, I acquired data from the first and second half of the season for each of these players. I scraped metrics such as home runs (HR), at-bats (AB), on-base plus slugging (OPS) and slugging percentage (SLG) using the baseball-scraper Python package. I used statistics from the season that each player participated in the Derby and chose July 15th as the average date of the divide between the first and second half.

From my initial review of the results, it was clear that there exists a significant drop in the number of home runs from the first half to the second half of the season amongst these players. The average first half number of home runs was 19.8, whereas the second half averaged only 11.7, a drop of 8.1. OPS also saw a drop from 0.913 to 0.834. Perhaps these results formed the basis of the conception that the home run derby negatively impacts players in the second half. These are staggering drops; however, there are some reasonable explanations.

Firstly, home runs are a count, not an average, meaning that if players have fewer at-bats, they will ultimately have fewer home runs. Since the first half of the season is typically longer than the second half, it makes sense that the number of home runs would be less. Of those who participated in the Derby within the last ten years, the average number of at-bats in the first half was 320, whereas the second half average was only 229. With approximately 90 fewer at-bats, a drop of eight home runs seems inevitable. Therefore, I decided to use HR/AB for all further calculations.

Secondly, the drop in OPS doesn’t reveal anything without comparing it to the rest of the league. Perhaps the entire MLB sees a decrease in offensive production in the second half of the year, simply due to the fatigue from the long length of the season. For this reason, I decided to also collect the first and second half data for the entire league since 2010.

Results

First, let\’s look at the results from the recent participants in the Home Run Derby.

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HR% is calculated by HR/AB, i.e., the percentage of at-bats that results in a home run. Results are taken from Home Run Derby participants 2010-2019.

Here we can see that a drop exists in each of these major offensive statistics. This means that, on average, Home Run Derby participants experience a loss of power from the first to the second half of the season. However, it is important to compare these results to the entire MLB.

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Results are taken from each player, each year from 2010-2019 that met a threshold of over 50 at-bats.

Surprisingly, the league average for HR/AB increases slightly in the second half of the season. However, OPS and SLG see a decrease of 0.021 and 0.015, respectively. In comparison to the drops experienced among Home Run Derby participants, these differences are minimal.

Despite these seemingly conclusive results, I decided that they were not sufficient. Those who participate in the Home Run Derby are experiencing an incredible first half. Their average OPS of 0.913 is spectacular, and to truly understand these drops, we need to investigate those who had similarly remarkable starts to the season. This comparison to the whole league is necessary, but frankly, these players are in a league of their own and should be evaluated accordingly. Naturally, this means taking a look at players who had an All-Star-worthy first half.

To answer this question, I formed two thresholds to create two distinct season types: All-Star-worthy and Home Run Derby-worthy. The results can be seen below.

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Results are taken from players who qualified as having an All-Star first half offensively. I set this threshold as a minimum of 15 home runs and a minimum OPS of 0.88.

\"Results

Results are taken from players who qualified as having a first half worthy of participating in the Home Run Derby. I set this threshold as a minimum of 18 home runs and a minimum OPS of 0.88, because almost every participant in the last 10 years met this standard.

Players who met the threshold for an All-Star-worthy season saw a drop of 1.3% in HR/AB and 0.084 in OPS. Similarly, potential Home Run Derby participants saw a decrease of 1.4% in HR/AB and 0.085 in OPS. These results are very similar and even somewhat lower than those of the actual Home Run Derby participants, who experienced a drop of only 1.29% in HR/AB and 0.08 in OPS.

From the charts above, we can see that league averages remain very similar from the first to the second half, while All-Star candidate averages experience significant declines in both metrics. It is quite clear that the Home Run Derby itself is not contributing to this decrease in offensive production in the second half. So, if not the Home Run Derby, then what?

Discussion — What other factors affect MLB hitting rates?

We can see from the results above that not only Home Run Derby participants encounter less productive second halves, but also All-Stars in general. In theory, this makes sense. Those selected for the All-Star Game are done so because they have an incredible, above-average start to the season. The expectation that these players will maintain this level of play throughout the entirety of the lengthy MLB season is simply unrealistic. Eventually, the law of averages comes into play, and players return to their normal level of play. 

While some extraordinary players don\’t experience this drop in statistics after participating in the Midsummer Classic, inevitably, many players will even out their metrics in the season\’s second half. This accounts for the consistent average drop among All-Star players that is not seen in the league as a whole. 

Another potential additive to this decline in offense may be attributed to the lack of rest that All-Stars experience. While the rest of the league receives a well-deserved break over the All-Star weekend, those who participate in the Home Run Derby and All-Star game do not benefit from this mid-season intermission. Regardless, it is evident that the recurring myth that the Home Run Derby negatively influences second-half production is, in fact, a myth. 

While there is always the risk of injury, there is no conclusive evidence that the Derby itself is detrimental to players. Some players like Giancarlo Stanton and Joc Pederson even increased their offensive contributions in the second half while still deciding to participate in the event. There will always exist the argument that the Derby causes overswinging or extreme fatigue to players. However, it can be quite conclusively said that Home Run Derby participants do not experience any more detriment to their second-half than that of the league\’s best who did not participate. 

Declining MLB hitting rates: The Jose Bautista Case Study

Blue Jays fans can agree that Jose Bautista will go down as one of the club\’s best home run hitters of all time. Bautista topped the MLB in home runs for two consecutive seasons in 2010 and 2011 while also participating in the Home Run Derby on three separate occasions. Without question, his numbers are impressive. However, many believe that his Home Run Derby appearances negatively impacted him later on. So, let\’s take a closer look. 

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In 2011, Bautista hit 31 home runs before the All-Star break. After the Derby, his home run percentage dropped by about 4.5%, along with a decrease of 0.28 in OPS. 

Despite the significant decrease, it is hard to argue that Bautista could have kept up his numbers from the first half. Bautista was on pace for a 62-home run season, a feat that nobody\’s achieved since Barry Bonds hit 73 in 1999. There was very little chance he could maintain this level of play, and it is difficult to argue against Bautista\’s offensive performance as he took the home run title for this year. 

Next, we move to 2012. Bautista had another stellar first half and an impressive appearance at the Derby, losing in the finals to Prince Fielder. However, just days after the All-Star break, the Blue Jays placed Bautista on the DL with a wrist injury. He attempted to return to the field in late August, but the injury quickly returned. Bautista missed virtually the entire second half of the 2012 season, and naturally, fans were quick to blame the Derby Curse. Certainly, there is a case to be made that overwork in the competition contributed to this injury, however, Bautista insists it was simply a fluky swing. Many people believe that Bautista never fully recovered after the tear to his wrist in 2012, but in 2014 he made his long-awaited return to the Home Run Derby. Bautista faired quite well, making it to the semi-finals before losing to Yoenis Céspedes. More impressive were his second-half stats, where he increased in HRs, HR% and OPS.  

Overall, it\’s difficult to say if the Home Run Derby negatively impacted Bautista\’s incredible home run-hitting resume. The decreases he experienced were expected, and his ability to improve for the second half in 2014 is remarkable. Nevertheless, people will continue to wonder if his participation in the Derby ultimately led to the crushing injury that initiated the decline of his career. 

All in all, it is hard to definitively say if the Home Run Derby will have long or short-term effects on hitters\’ power and performance, but it is fair to say that one night of fun for the fans will most likely not be the sole reason for your favourite slugger\’s drop in second-half performance.

Statistics retrieved from Baseball-Reference, FanGraphs, and Baseball Prospectus

Cover photo credited to Getty Images

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