grad school

So I don't know what the deal is with grad school, but someone has to know the trick. Is it easier to get in to the school where you went to undergrad, or are your chances better if you apply to schools far away. Or honestly does it not really matter.... it all just depends on chance. Hearing where some people have gotten in to compared to where others have blows my mind everyday. I think im just going to apply to schools everywhere and see what happens when the time comes.