<p>There is very little true randomness even among the top schools. The admissions are not decided by a lottery or by throwing darts. Human beings are making the decisions, and every candidate is accepted or rejected for a reason or list of reasons. It's just that the reasons are often not captured in the cut-and-dried "stats" amd thus not visible to those of us who are outside the process.</p>
<p>A more accurate way of expressing this is not that the process has some randomness, but rather that it has a degree of subjectivity.</p>