Yes I said random. If you have two spots and after you've spend weeks discussing things, and you've narrowed things down to five great candidates, then at the end of the day, who gets chosen is pretty much random. They don't literally flip coins, but they use criterion that might as well be coin flips.
Candidate A has a 3.8 GPA and a 860 PGRE. Candidate B has a 3.9 GPA and a 840. Professor C happens to think that PGRE's are much more important than GPA's, but unfortunately for candidate A, his plane back from Europe was delayed so he missed the meeting where they set the cutoff, and his asked Professor D to substitute for him, and Professor D hates the PGRE. Not to mention that the fact that Candidate A got a 3.8, because he had a cold the day of the German final exam, and took too much flu medicine.
Having randomness in graduate admissions is something of a good thing. If it really is random, then it means that you have a different set of coin flips in different schools, which means that if you apply to a decent number with a decent application, you'll get in somewhere.
It should also reduce some of the fear that you see on the forum. People are terrified that if they make the wrong decision, they are doomed. You should worry less if you realize that what is the "right" decision and the "wrong" decision is somewhat random and out of your control.