Mizuno representatives visited the NPB offices on Monday and met Commissioner Katsuhiko Kumazaki. They provided the NPB with an updated report that they were able to establish a stable supply of standard baseballs that fulfilled the league's necessary requirements.
Tests conducted after the start of the season revealed substandard baseballs that had coefficient of restitutions that were higher than what was allowed by the league. An investigation uncovered problems in the manufacturing and testing process. Additional tests were conducted on baseballs in stock to separate the good from the bad. The league switched over to "certified" baseballs once they were able to confirm a large enough supply. Mizuno made changes to the manufacturing process to avoid future incidents and was able to provide the league with assurances on Monday that they would be able to deliver a steady supply of the certified baseballs.
In addition, on Thursday last week, Mizuno president Akito Mizuno told reporters they were still not sure what to do with the baseballs that failed to meet the NPB's requirements.