The NFL first reported team game sacks in their weekly stats in 1964. They showed team totals for the season starting in 1963. Team sacks are therefore considered "official" since 1963. They reported sack yards lost in the game stats starting in 1952. We have game-by-game sack yards lost for most teams back to 1947.

The AFL did not report sacks or yards lost in their weekly stats until 1967 but did in their game books, so we were able to fill that all in back to 1960.  In 1960 they counted sacks as runs, per the college rule, but we subtracted out all those runs and put them in the sack column.