How does the "popular post" thing work? Cause I'll see posts with minimal comments on there then a…

How does the "popular post" thing work? Cause I'll see posts with minimal comments on there then a post with 4x the comments is in the regular feed. It might just be me but I'd rather see the posts with the most comments/active discussion. (That could also eliminate a lot of "what happened? Tag me in it, send me screenshots" Posts)