how are points allocated

All you need to know is the following:
*The more games you've played, the less your rating will fluctuate
-If you win/draw against higher rated players, you gain more points.
-If you lose/draw against lower rated players, you lose more points.
*If you play against someone very established, your rating will fluctuate more.
What happens if I win against an equal opponent at the start of the game but when it is over he has lost loads of points playing other games

It is your opponents rating at the end of the game that matters.
If you want to read some more about how the rating system works:
https://www.chess.com/article/view/chess-ratings---how-they-work
I used to get 8 points for a win against an equally rated opponent, but all of a sudden now I am getting only 4. Could someone please explain what the rule is behind this?

I used to get 8 points for a win against an equally rated opponent, but all of a sudden now I am getting only 4. Could someone please explain what the rule is behind this?
same

If your opponent has a high RD (ie: a poorly established rating) then you will gain or lose fewer points.
That might explain why you only gain or lose 4 points instead of 8 to an equal rated opponent... his RD is high and his rating is only approximate.
Read up on the Glicko rating system.


If your opponent has a high RD (ie: a poorly established rating) then you will gain or lose fewer points.
That might explain why you only gain or lose 4 points instead of 8 to an equal rated opponent... his RD is high and his rating is only approximate.
Read up on the Glicko rating system.
having the same glicko [16] for months and I was winning or losing 8 ps

I hope it is a bug! Cause in the other hand my glicko rd remains at 16 and I think that is what it represents...16 points on the table. +8 -8 or +9-7 etc. And its more fun I think...
You are right, it makes sense that it is an existing rule never actually applied before. In a similar fashion, two of my opponents' accounts were closed yesterday for cheating, I got back one of the lost set of points (not both), none of these happened before. There is even a chance that the chess.com guys started doing their job.