There are two common trains of thought (apart from OP constantly spewing out Jayne’s little 33 percenter).
1 - “If you’re good, you’ll climb”
2 - “A 50/50 winrate is fair”
On their own, both those statements are true. Together, they are fairly opposed.
Say I’m some master/GM player and I fall to diamond or even plat, arguably, you could say, “well you have a much greater chance to win because you have a higher skill level!” In most any other game other than OW, that’s quite true and is the way it should be.
Enter: Matchmaker.
The matchmaker is programmed to not give either team a predicted win percentage of under 40%. Meaning, there is always an algorithmically predicted outcome of winning ~40%-60% of the time for either team, otherwise the match isn’t even made.
This was mentioned in the dev post here:
‘Groups and Matchmaking in Overwatch’
I want you all to read this next sentence really slowly to emulate me saying it slowly so you can understand.
That. means. no. matter. how. good. you. are. it’s. still. going. to. be. a. 40% to 60%. chance. of. you. winning.
Be it stacking better players on red and/or worse players on blue. SR is not used in matchmaking, MMR is. Jeff said it at 8:29 through to 8:43 on this video:
‘Seagull & Jeff Kaplan: NEW Hero Confirmed! - YouTube’
…or as I like to call it, “The moment it was made public that SR means literally nothing”.
This means if you fall to an ELO where you don’t belong, you will be put against other players who also don’t belong there to maintain the 40%-60% winrate. You will not be against golds in gold and you will not be against plats in plat.
For the matching to be objectively fair, the better player should have a higher chance of winning. Matchmaker says no. THIS is why players are often locked in ranks they don’t belong.
If we think a little logically for a second, I know that’s a reach for some of you, this also means that the inverse of this is true; if you manage to reach an SR that’s higher than your MMR, the matching is actually going to work in your favour by putting better players on your team to maintain the 40%-60% predicted winrates. Likely obtained either by luck, flipping the coin or boosting. Also explaining why some people seem to be totally fine in an SR range much higher than they belong. Looking at you, Mercy players. Hahah I’m jk (slightly).
N.B. Obviously there are external factors that will deviate the predicted winrate to the actual winrate but if the MMR is as accurate as all the forum goers tout cause it’s trendy, it shouldn’t deviate much.