This has all been explained in other threads.
Your rating is calculated by the number of new posts you create as compared to how many responses it generates, along with how many likes, happy faces, crying faces and so forth you get and from whom on what day and what time of day.
Further, your own likes and happy faces and thumps up and sobbing faces are recorded, again in ratio to who you give them to at what time of day and how many are new people.
Next, deductions for people who you have or have you on "ignore".
Your activity is constantly tracked in a sophisticated software program that assists the A.Dot in generating these ratings.
Finally, the A.Dot office staff starts doing shots, pull's user names out of one hat and numbers from the other and updates the ratings without regard to all of the above. (This was basically confirmed by the A.Dot Head Shed a couple of weeks ago.........basically.)