From SABR member Jay Jaffe at Deadspin on August 29, 2012:
Perhaps more than any other culprit, “juiced” baseballs could explain the rise in home runs during the Steroid Era. Unfortunately, much of the evidence for changes in the ball is indirect, accompanied by a generous helping of anecdotes, and cloaked in perennial denials from manufacturers and other officials. Still, unraveling the truth about what may have changed inside the baseballs—and how those changes could have contributed to the home-run boom—isn’t an impossible task given enough patience to sift through the literature on the topic.
Recall that the switch from Spalding to Rawlings as the supplier of major league balls in 1977 coincided with a 50 percent jump in home runs across the two leagues. The 1977 rates weren’t unprecedented; both leagues had been at similar heights as recently as 1970, itself a spike year for homers. The 1976 rate of 0.58 homers per game was the lowest since 1946, even lower than 1968. Prior to the switch in manufacturer, the last major change to the ball had come in 1974, when the outer coating switched from horsehide to cowhide because of a shortage of the former. Homer production fell from 0.80 per game to 0.68, a 14.7 percent drop. It increased 2.4 percent in 1975, but then fell off another 17.4 percent in 1976.
Given those ups and downs, it’s possible that Spalding didn’t perfect the process of using the new covering before surrendering the manufacturing process to Rawlings, or that the balls used at the end of their run were leftovers that were slightly substandard in resilience, leading to the dip in home runs. It would take a Deep Throat to provide insight into the matter, but unlike in the Watergate scandal of that decade, none has ever come forward. In any event, aside from 1976, the rises and falls around that time fit right in with the garden-variety season-to-season variation in the expansion era.
Read the full article here: http://deadspin.com/5937432/was-mlbs-juiced-era-actually-a-juiced+ball-era
Originally published: August 29, 2012. Last Updated: August 29, 2012.