Excessive Throwing: How Many Pitches of Japanese High School Baseball Players Violate Pitch Count Guidelines

Category: Best data-driven reporting (small and large newsrooms)

Country/area: Japan

Organisation: Toyo Keizai Inc.

Organisation size: Big

Publication date: 22/08/2019

Credit: Kazuki Ogiwara

Project description:

The national high school baseball championship is one of the most popular sports events in Japan. It is a great honor to play there for players.

However, pitchers are often forced to throw far beyond the appropriate range. Referring to Pitch Smart, an American series of guidelines for youth baseball players to avoid overuse injuries, we published an infographic and an article to show how Japanese high school baseball pitchers are exposed to the risk of injury.

Impact reached:

The most important impact of this project is that it revealed high school baseball pitchers in Japan are throwing far beyond the usual range, and most of them are due to violation of a regulation of rest days. In Japan, there are no guidelines or rules on youth pitchers that limit over-pitching. Since many teams (schools) do not have enough pitchers to rotate them, the pitchers in such teams often had to pitch complete games during the tournament. In this infographic, we displayed the 10 pitchers who threw the most in this tournament after 2000, and applied two rules from Pitch Smart to their pitches. Pitches that violate the daily limit (105 pitches at the age of 17 – 18) are displayed in yellow, and pitches that violate the rest day restrictions (4 days after throwing more than 81 pitches) are displayed in red. While pitches that violate neither are displayed in white, they may still conflict with other rules of Pitch Smart. This infographic shows that high school baseball pitchers are forced to throw excessive pitches, and especially they do not have enough rest days. Since the number of teams gradually decreases later in the tournament, they often have to throw several days in a row. For instance, Yuki Saito (斎藤 佑樹), the pitcher who threw the most in this graphic, threw 948 pitches in 16 days. 88 of them violate the daily limit, and 545 of them violate the rest day limit. 553 pitches were thrown in the last 4 days, including the final and its rematch. After this project was published, this problem drew attention on traditional media such as TV and social media such as Twitter. As a result, in November 2019, Japan High School Baseball Federation decided to make rules against over-pitching for their first

Techniques/technologies used:

Since this infographic needed daily pitch counts of each pitcher, we collected the data from the past baseball news from newspapers and magazines.

The data was converted into JSON file. P5.js was used to draw the graphic.

What was the hardest part of this project?

The hardest part of this project was how to convey the seriousness of this issue to readers who are not familiar with baseball.

While the total numbers of pitches on each players are sometimes shared on SNS, just the numbers did not explain how much the youth pitchers are at risk of overuse.

Initially we tried to compare to professional baseball, where all teams have enough pitchers to rest them, but since many conditions such as match interval or rules of the tournament, we concluded this comparison is not appropriate.

Then we decided to apply Pitch Smart to Japanese high school baseball. How the Japanese tournament violates the guidelines of Pitch Smart clearly indicated the severity of the problem.

This comparison also revealed that the biggest factor of this over pitching is a violation of a regulation of rest days.

What can others learn from this project?

What other newsrooms can learn from this project is that storytelling by data changes depending on the comparison axis setting.

While the total number of pitch counts of each pitcher in the past tournaments was already published and shared, the seriousness of 

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