Elementary steps in war against injury

This past week, the civil war brewing within Japanese baseball over rules to protect pitchers’ arms heated up. On Thursday, the Japan Rubber Baseball Association adopted 70-pitch limits for the national elementary school baseball tournament this summer, and the rule did not pass without a fight.

Prefectural and regional federations will have a year to adopt the rule.

The national federation announced the following guidelines:

Guidelines

  1. All players will be limited to 70 throws at full strength per day in practice and 300 a week.
  2. Practice will be limited to six days a week, and not more than three hours in one day.
  3. Players should not appear in more than 100 games a year.

The chief executive of the national federation, Toyomi Munakata, said that over the past five years, national tournament games saw an average of 100 pitches thrown per team.

“I want to protect the rights of the children and their enjoyment of baseball,” Munakata said. “Through enactment of a pitch limit, I want coaches to change their policies.”

Same old song and dance

He said there was opposition from some on the federation’s board of councilors, who cited a phrase commonly heard the past two months “we can’t enforce such a rule because there aren’t enough pitchers.”

This was an objection heard frequently in December when Niigata Prefecture’s high school baseball federation announced it would introduce pitch limits at its spring tournament and moved ahead without seeking approval from the national federation.

The crux of the problem

On Saturday, Dr. Kozo Furushima, Japan’s most prominent Tommy John surgeon, told me that young pitchers are susceptible to suffering inner elbow fractures from placing too much stress on the elbow of the yet-immature bones in their elbows.

“Adults’ bones are hard and the ligaments are a big concern, but when children are in elementary school and junior high school, it is the other way around,” Furushima said. “The bones in children’s joints contain a lot of cartilage and are not rigid. The part of the bone where the ligament attaches can be pulled away from the rest of the bone, creating a fracture.

“Children will not feel pain or be hindered in ordinary activities but when they put a lot of stress on the damaged elbow, they will feel pain. And those that go untreated will often result in injuries later as the joints mature.

Furushima is the chief of the Sports Medical Center of Keiyu Orthopaedic Hospital in Tatebayashi, Gunma Prefecture, north of Tokyo. He said that of the 301 youngsters treated at his facility for inner elbow disorders, 81.3 percent reported practicing an average of five or more hours every Saturday and Sunday. The group of patients practicing 3 to 5 hours made up another 12.6 percent of the group.

“It’s not just pitching in games, but how much and how hard kids are throwing in practice,” he said.

The next phase of the debate is poised for the coming week, when the national high school federation is expected to lower the boom on authorities in Niigata for acting on their own to enforce pitch limits.

Strike while the iron is hot

While we’re on the subject of called balls and strikes in Nippon Professional Baseball, @Student_murmur has done a nice study in Delta Graphs about how the count affects umpires calls, which you can find in Japanese HERE.

Lacking pitch tracking data and having to depend on Mark I eyeball technology, the researcher drew a line around the strike zone in different counts where calls went 50-50. It’s no surprise that the smallest zone accompanies the 0-2 count, and the largest the 3-0 count.

The data from 2017 and 2018 collected by Delta Graphs looks fairly consistent and are consistent with the findings of John Walsh in 2010, which you can find HERE. Walsh found that the area of the strike zone’s vertical plane in MLB was 3.52 square feet with a 3-0 count and 2.42 square feet with an 0-2 count.

The last post here dealt with pitch locations derived from Nikkan Sports’ pitch-by-pitch data in 2018. These consisted of designated as inside the edge of the zone and outside the edge. I labeled them all borderline pitches, either borderline ball locations or borderline strike locations.

Looking at pitches in these two border zones that were called balls and strikes on 3-0, 0-2 and all other counts in 2018 produces the following tables, where 78 percent of all borderline pitches were called balls in counts other than 3-0 and 0-2. In 3-0 counts it was 60 percent. In 0-2 counts it was 92 percent.

We need to understand that in this study and the Delta Graphs one, the data points are being observed by someone else’s eyeballs and recorded by someone else’s hands. Also, pitchers can worry less about balls and strikes in certain counts. Unfortunately, the same seems to go for umpires.

Borderline called NPB balls and strikes in 2018 with 0-2 counts

CountBorder ZoneBallStrikeTotal
0-2Strike Zone1182183
0-2Ball Zone2,12242,126
0-2Total2,1231862,309
Percent91.94%8.06%

Borderline called NPB balls and strikes in 2018 with 3-0 counts

CountBorder ZoneBallStrikeTotal
3-0Strike Zone0349349
3-0Ball Zone5243527
3-0Total524352876
Percent59.82%40.18%

Borderline called NPB balls and strikes in 2018 with all other counts

CountBorder ZoneBallStrikeTotal
OtherStrike Zone211,06011,062
OtherBall Zone39,50413539,639
OtherTotal39,50611,19550,701
Percent77.92%22.08%

writing & research on Japanese baseball

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