THE BOOK--Playing The Percentages In Baseball

Thursday, March 17, 2011

Deadening balls

Wonderful stuff:

Digging a little further revealed a turning point for this NL homer rate in ’67:

April 2.56%
May 2.64%
June 2.99%
July 2.60%

August 1.82%
Sept/Oct 1.89%

Wow. That looks to me like something happened to dramatically reduce homers either at the beginning of August that season or somewhere in the back end of July.

In 1968, that low rate resumed:

1st half: 1.94%
2nd half: 1.95%
April 2.37%
May 1.69%
June 2.04%
July 1.72%
August 2.03%
Sept/Oct 2.00%

And the possible cause:

“Rawlings had ... six manufacturing plants--four in Missouri and two in Puerto Rico--when it was sold in 1967 to Automatic Sprinkler Corp. of America. This conglomerate made the company a division under its prior Rawlings Sporting Goods name.”

It seems a remarkable coincidence that a change in home run rates should come in the same year that the ball manufacturer changes ownership.