WHEN EACH UMPIRE MADE HIS OWN RULES.

WHEN EACH UMPIRE MADE HIS OWN RULES. It’s not so long ago that each major league umpire had his own strike zone–and was proud of it. These strike zones were often lower and wider than what the rule book specified. Sometimes, those individual strike zones changed during a game. Pitchers spoke of “working with” the umpire to expand the strike zone. This wikipedia article on changes in the strike zone led me to this article from 2007 on how knowing the home plate umpire could help you bet the over/under on a game. Darrin Jackson, who played for a couple of years in Japan, has said that one of the big adjustments for Japanese players who came to the United States was to get used to the fact that the strike zone changed from day to day.