I think the rankings are based on the papers that people save. There is a separate page for Twitter based rankings, which seems noisier (ie top paper from the l

I think the rankings are based on the papers that people save. There is a separate page for Twitter based rankings, which seems noisier (ie top paper from the last month is about Hearthstone). It does seem that survey/review/tutorial type papers are slightly over represented. No ranked list is ever perfect, but this passes the eye test IMO.