Jaffe: A juiced baseball scandal in Japan

From SABR member Jay Jaffe at SI’s The Strike Zone on June 12, 2013:

League officials have copped to juicing baseballs in order to raise offensive levels. If that sounds like the light shining on a dark conspiracy regarding the high-offense era that ran through Major League Baseball from the mid-1990s to the late 2000s, it’s not, though such a revelation is on my wish list. Instead, it’s actually what has transpired in Japan, which is currently amid something of a home run boom.

According to the Bangkok Post, after repeated denials, officials from the Nippon Professional Baseball have admitted that they asked equipment manufacturer Mizuno to alter the specifications of the ball in order to increase offensive levels, though that was to counteract a previous alteration. Back in 2011, NPB commissioner Ryozo Kato — who oversees the Japanese Central and Japanese Pacific Leagues — ordered a change in the makeup of the balls, which were slightly smaller and lighter than those used in MLB, to bring them in line with the stateside model. Wrote the Post, “The cork core of the ball was wrapped with a low-resilience rubber and its seams were widened. The organisation also made Mizuno the sole ball supplier, dropping its three rivals.”

With the new ball, home runs rates dropped by more than 40 percent, from 0.93 per team per game in 2010 to 0.54 per game in 2011 and 0.51 per game in 2012 according to data from Baseball-Reference.com. The players’ union, which felt that games had become less interesting, asked the league to review the matter. This year, the rates are back up to 0.75 per team per game, an increase of 47 percent but still well shy of pre-tinkering rates. From 2001 through 2005, they were above 1.0 per team per game, with a high of 1.25 per game in 2004. By comparison, in MLB, home run rates rose above 1.0 per game in 1994 and have been there ever since except for 2010 and 2011, peaking in 2000 at 1.17 per game; they’re currently at 1.01 per game.

Read the full article here: http://mlb.si.com/2013/06/12/japan-juiced-baseballs/

Originally published: June 12, 2013. Last Updated: June 12, 2013.