In this question I brought up two rating systems and wondered which is used by FIDE.
Briefly, they are:
Method 1 Ratings are updated (recalculated in other words) after every match.
Method 2 Ratings are recalculated after a specific period of time, say after a tournament or once a month.
I found out that FIDE uses method 2 (recalculates ratings once a month).
My question
Why doesn't FIDE recalculate ratings after every match?
Is there some kind of statistical problem with that? I don't mean to be partial to either method, but there must have been a compelling reason for FIDE to choose method 2 over method 1, and I'd like to know what that is.
I always thought recalculating the ratings match after match would make the system more accurate, but I'm not an expert, so I can't be sure.