Pearson, as an active contributor to the biology learning community, is pleased to provide free access to the Classic edition of The Biology Place to all educators and their students. The purpose of the activities is to help you review material you have already studied in class or have read in your text.
In modern day baseball, teams generally have five starting pitchers, and they take it in turn to start a game every fifth day (hence the phrase rotation). Sometimes, if the schedule pans out, a team can get away with a four man rotation, and in the distant past some teams managed a three man rotation.
The number of balls used is 46. Factoring this number out to each team in the league playing 165 games and dividing by 2 since two teams play each other each game, the number of baseballs used during a typical MLB season would about 113,850 balls per year.