This is a recurring answer.
Sometimes things happen that look very strange (as an example: I assume that a win against weaker or a loss against a stronger opponent should reduce the uncertainty or confidence or deviation or whatever it’s called).
The fact that the algorithm is complicated doesn’t hearten much.
Many users are complaining or doubtful about rating, but we obviously can see a very little part of the ingredients: our games, our rank, the changes after a game…
I believe that our devs could share more informations and get a big reward from it, at least in terms of happier users. Many of us would be very happy to participate as “testers” and this could be win-win: if everything is ok, we’ll be reassured, and if we find out that something was wrong, they could fix it.
We do this every day about everithing else on OGS, but rating is a big black box.