Mizuno received a new shipment of baseballs from their factory in Shanghai last month (about 1,300 cases of twelve). They passed preliminary tests and were awaiting checks on coefficient of restitution. The NPB announced today that the shipment was tested and approved.
Six cases were tested by the Japan Vehicle Inspection Association in Tokyo. The average coefficient of restitution was 0.414. The range was between 0.411 and 0.417. Both figures fell within the required limits (from 0.4034 to 0.4234).
Approved baseballs will be introduced to Ni-gun games once a stable supply has been established.
[UPDATE 6/9 @ 4:31pm]
The NPB posted the following information about the test:
Coefficient of Restitution Tested on: June 2, 2014
Number of Balls Tested: six boxes of twelve
|Sample Name||Avg CoR|
Coefficient of Restitution Limits: 0.4034 to 0.4234
Source: official announcement