??? is a valid score in the new algorithm.
Doesn't that mean if someone receives a positive and a negative rating, they'll go negative if the negative is newer?
If someone has 1 positive and 1 negative, then the time doesn't matter. They'll have a score of -1.
Examples:
Old -> New
+ - : -1
- + : -1
+ + - : ???
+ - + : 0
- + + : 1
+ + + : >=3
- - + : -3
+ - - : -3
- - - : -8
That seems like quite an extreme decay, ratings after 10 months are worthless? Its going to lead to a lot of reposted ratings to refresh them.
There is no decay. Ratings grow in weight from 1 to 10, then stay at 10 forever. (If the rated person has no negatives.)