Personal performance only counts towards your initial ranking. After that you uprank for winning and downrank for losing. So, basically it's as broken as you stated custard.
So then how do such bad people get higher ranks, other than what I described? Btw, I didn't mean to state it as a fact, just saying how I think it works after playing, as I've carried these people before, which results in them ranking up. Hence my theory.
Except that isn't how ranks are given out at all.
Being matched up with people who are placed in the same skill rank as you, but play like they should be in a way lower one.Oh my god this.
The ranking system is so broken, a scrub can be placed on a winning team ten matches in a row, get 3 kills and 15 deaths, team carries them, and they get diamond (or similar ) rank.
Played in the same 10 qualifying arena break out games as 3 friends. I got Diamond, 2 got Platinum and 1 got Gold.
I suggest they implement you KDA dynamically into your rank. What I mean by this is, KDA has a higher influence in slayer type modes, and have another count for objective caps/carries/assists for objective playlists. Then have win/loss take effect after this. Therefore, teamwork and winning is still important in ranking up, but this rank up will scale based on your personal skill. So in short, if you have a high personal skill(I.e KDA for slayer, and Caps/Carries/assists for obj) and you win, you you rank up more/faster than you would if you had lower skill but you still win. This ensures that players who play as a team rank up, and those who have a higher personal skill will rank up quicker so that they don't get demoted by the player who get put on good teams (I have been demoted/out in low rank) so many times.
Then on top of that, they make it clear what level of skill and wins is needed to be in said ranks. Currently, I can encounter a diamond player who is worse than some gold players, and vice versa.