Outline of years when certain rules were used

Goal Post Position
1951-1973  Goal Line
1974-Present  End Line

Kickoff Line
1951-1973  40 yard line
1974-1993  35 yard line
1994-Present  30 yard line

Field Goal Miss Line
1951-1973  20 yard line
1974-1993  Line of Scrimmage
1994-Present  Kick Spot

These rules, along with Rules Year, are to be edited in your Rules window in accordance to the year your team is from.  So that when you play home games the rules your team played with will be in use.