Interesting as well is this story....
Company claims 1998 baseball 'juiced'
http://tsn.ca/mlb/news_story/?ID=190832&hubname=mlb
A company that uses computer imaging claims baseballs had a larger rubberized core and a synthetic rubber ring in 1998, including the ball Mark McGwire hit for his 70th homer.
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"Examining the CT images of Mark McGwire's 70th home run ball one can clearly see the synthetic ring around the core - or 'pill' - of the baseball," UMS president David Zavagno said. "While Mark McGwire may or may not have used illegal steroids, the evidence shows his ball - under the governing body of the league - was juiced."