Six-game series among changes to minor leagues NEW YORK -- Baseball's minor leagues will shift to regionalized six-game series with a common off day in a move that cuts scheduled travel mileage by 28-56% and reduces expenses in their first season of operations under Major League Baseball. MLB reduced affiliated farm teams to 120 from 160 in the first season after the end of the Professional Baseball Agreement between Major League Baseball and the National Association of Professional Baseball Leagues, which had governed the minors. The PBA had existed since 1901 but was allowed to expire at the end of 2020 as MLB took over running the minors.