How does stadium rank progression work?

First of all, what exactly are “stadium points”? Are they like SR? I noticed that I have 3075 stadium points and that I am “Pro 5”, but how are these two related? I noticed that in the progress bar that is displayed after each game, it doesn’t show the percentage that the bar has increased or decreased by, like in a normal competitive game (e.g. “+25%”), but instead it just shows “+100” without the percentage, so I assume this is the number of points you have won or lost in a particular game. What confuses me, and many other players as well, is that sometimes the amount the bar moves up and down doesn’t seem to be related to the number of points won/lost. Sometimes I win 125 points and the bar moves up by a quarter, and sometimes it says “-50 points” and the bar moves down by a half. So here’s the question: how are stadium points related to rank progression?

I have no clue also. its random.
I lost 10 games in a row, in elite 4, went down elite 5 … and won a couple games, +5, +10 … won 6 games in a row.
and then lost ( where i had 80k+ mvp points or wtv).
and lost -50 …
like wtf