A common misconception in here that I can help clear up: You CAN go up against lesser opponents if that situation does happen.
As a reminder,
SR is your Skill Rating, which is your accurate long term measurement of your Skill over time. This is not visible to players and we run multi-day calculations at the end of the season to
TSR is your Tier Skill Rating, which you see on the website. This is what we reset seasonally.
So with that in mind, here’s how it works:
Your Skill Rating dictates your ability for your Tier Skill Rating to progress, drop, or stall. If your Skill Rating is above your current Tier Skill Rating, wins will progress you further towards matching your TSR value and your SR value.
Conversely, if your Skill Rating falls below your Tier Skill Rating, your TSR won’t progress until your SR exceeds your current TSR. This is why sometimes you will stall or only move when you lose, as the system adjusts you downwards towards your Skill Rating.
There are instances where a loss can drop some TSR even though your SR exceeds your TSR if the two are getting pretty close together (and the same applies conversely for wins).
SR is all based on your performance against players based on their skill, and your individual performance within those games. That’s the ‘quality’ measurement of the system. TSR is simply moving towards your SR over time, with wins progressing it and losses regressing it (if your SR is lower).
Another note - at the higher ranks (generally Onyx 3 and up), you get into percentiles of Skill difference between players. At this stage, one bad performance against players you were expected to perform much better than can cause the sudden drops after slow progress.
This isn’t the SR being overly punishing, rather it’s your SR dropped enough to have a much larger impact (and therefore drag your TSR with it) due to the much closer skill percentiles.