Players will be matched with enemies that are above/below their usual matching limit if they win/lose a lot. If someone usually plays with newbies but beats most of them, this might push them into a game with some of the stronger players. Even if they're not actually good enough to have a chance.
This will make it harder for the very top and very bottom players to get repeated matches, if there are few other players online. Usually you'd expect there to be more players in the middle ranks than on the outer edge, as long as that is the case, they will just take turns in fighting the outliers.
It does not have any effect on the first match after some inactivity, but when you repeatedly get Godde'd it will try to prevent you from being matched again.
Edit: I should make clear that this only looks at your win chance, not whether you won. If all of your games are a 50% win chance and you still lose, this has no effect whatsoever. It will only try to prevent repeated "unfair" matches, based on your current rating.
