i am going to win a game against someone whos rating is 400 over mine.

at the same time, im losing to someone 200 less than me

?

I bet you can't beat me no matter how hard you try

The rating difference just gives you an idea of the probability of winning or losing.  So it is certaintly possible to beat someone 400 points higher.  But the chances of you doing it consistantly are low.

Also the ratings don't take into account how consistant the players are.