1982 is the magic year for pass-rushing records in the NFL. That season, the league began counting sacks as an official statistic, helping give pass-rushers an easy metric with which people could judge how effective a player is and was at bringing down the quarterback.
The modern value of sacks may be debated, and Green Bay Packers outside linebackers coach Mike Smith would surely be happy to have a spirited discussion about the value of pressures vs. sacks at any time. But sacks remain the single easiest number by which to judge a pass-rusher’s production. As long as they played after 1982, at least.