It has to do with a few factorsFirst is offensive systems and plays . Now , we have so many plays made specifically to free up shooters on the arc . They didn ' t just come out of thin air when the league introduced the arc though it was a slow trickle that resulted from innovation and iteration . Secondly , roster composition and specifically emphasis on the 4 and 5 . In the past , a lot more emphasis was put on big men playing in the post . This is why we hear Shaq constantly talk about the days of the Big Man . As others have already said , defenders weren ' t used to dealing with perimeter threats as well . There ' s probably a lot more but I ' m on my phone and lunch is almost up . Hope this makes sense and explains some of it .