>>15845824I don't know the exact mechanics, but you start at 1007 rating, the more you play, the more stagnant your rating is. If you win 10 times and have never lost, a win will effect your rating a lot less than a loss.
Also, you get more or less score depending on how big the difference between your rating and someone else's is.
I'd consider anything over 2000 in the current meta to be good, but once Pokebank comes out and official OU and Pokebank OU combine, 2200 and above would be good. Smogon thinks anything above 1850 is "knows what he or she is doing", and they have separate usage stats for Pokemon by people at or above 1850.