Simplify the following text for a Grade 11 native English-speaking person.
Original: The current standard of 130 at bats , 50 innings pitched or 45 days on the active roster of a Major League club ( excluding time in military service or on the disabled list ) before September 1 was adopted in 1971 .
Simplified: The current rule is 130 at bats , 50 innings pitched or 45 days on the active roster of a Major League club ( except for time in military service or on the disabled list ) before September 1 was first used in 1971 .