I was sure I saw these on Stratz but I spent 5 minutes looking and I can't find the page anywhere anymore. There was also one comparing some stats per rank and I also can't find it.

The ones about party lengths and "time of day" aren't actually stated tho. Those were just general impressions that were established, one because people kept talking about it, and the other because Dotabuff has a personal time of day winrate tracker (as well as winrate calendars) which help see how bad time of day messes with your performance.