So i just go promoted to platinum, and a bad day, got 3 "cancer teams" but it didnt demote me, so how many times can you lose to get demoted again? does it depend on mmr alot or just a bit? my mmr is average or slightly below, please help
Around 5 - 10 games lost will generally demote you. If you get games that go badly it's very easy to drop the same day you're promoted.
So if you see that your teammates have relatively bad stats (Low cs, High deaths, low Kills / assists) it will probably be better to just dodge rather than risk demotion.
Basically at plat level you're expecting a average cs of around 6 to 8 per minute and a death count of maybe around 5 per game with a average of 2.5 kda or so. Stats that deviate too far from that level show either horrible decision making or inadequate mechanics for that elo.
If you can't cs decently to near perfectly at this rank there is a problem. It's one of the easiest mechanics to pickup. Just tediously grind in customs till you never miss cs. There isn't much of a excuse for anything above mid gold in rank to not be able to consistently cs in the average case. Unless for some reason they have a string of 20 games where somehow they're zoned too hard to do so. (Mid plat - Diamond players have no excuse other than laziness to not get similar cs numbers to challenger / master players)
The exception on cs is junglers they should typically have around 3 - 7 per minute on cs unless they're literally split pushing the whole game (camps spawn slower, ganking makes routes inefficient).
