This is my solution to the problem of fluctuating ratings: Leagues. I'm *nabbing this idea from Outwitters; the idea is that you should be able to remain in the same league most of the time, as long as your rating only changes so much. Lets take the leagues from that game as an example and use them here:
And here would be the ratings to rise and drop from each league (for example):
**Fluffy: 1450 to promote to Clever
Clever: 1400 to demote to Fluffy, 1600 to promote to Gifted
Gifted: 1550 to demote to Clever, 1650 to promote to Master
Master: 1600 to demote to Gifted, 1700 to promote to SuperTitan
Super-titan: 1750 to demote to Masters
As you can see, there are no clear cut off points such as 'if you are above 1600 you are gifted, below you are clever'. The point is for you to stay in the same league consistently, so you don't constantly get promoted and demoted between leagues. I hope you like my idea, and remember, criticize constructively and if you don't like it, suggest how to improve it!
Spoiler: show