Can someone with more experience in this area help me understand how the officiating crews are rotated between conference games and how or if they are rated/scored as part of review process for job performance by the League???

I always thought they were randomly picked before the season as a crew and scheduled to work a game schedule same as the teams...but now I am not sure because I keep seeing a lot of the same crews working in the same conferences?? Is this my imagination??

It would seem to me that rotating crews throughout the League for the entire season would be a better way to ensure more of an impartial job by the crews. I mean if you see a lot of the same players week in and week out you might tend to form biases one way or the other subconsiously and consiously in some instances.

Any help understanding this appreciated......Cheers!