The final answer to your questions is, it’s a black box.
No one really knows and, even though they designed it, I doubt Blizzard does with certainty, either.
Blizzard promised the Bronze 5 placement bug was fixed in October.
It wasn’t. It turns out it was still a problem and needed to be fixed again on Nov. 17th. The thread below shows players stating there are still problems - after the fix for the fix on Nov. 17th.
Is it fixed? No one knows, not even Blizzard who is promising it’s fixed, when it’s really not.
I’ve been in software development for over 25 years. If you’ve made a hotfix (like the Bonze 5 bug) and discover the bug isn’t fixed (or causes another bug) then your code, QA and/or platform are more complex than anyone really knows.
You would think a positive win rate of over 50% means you would climb. It absolutely does NOT when you are in the metal ranks, thanks to the magic of performance-based SR.
Is a win a win and a loss a loss? Not really, not after performance-based SR calculations. If you win many, many games and maintain a win rate of like 55%, it can still mean (over time) you are losing rank.
Alas, here’s an attempt to explain how performance-based SR works. It’s from OW1.
I’m assuming it hasn’t changed but I could be wrong. Hope it helps.