I agree with USMA 1994:
It is a very hard road. In rough numbers, 10,000-12,000 complete their SA applications. Roughly 4,000 receive Congressional nominations, Approximately 2,400 of those nominated are considered "qualified academicly and in physical aptitude". (Notice it doesn't say qualified medically -- qualified physically means CFA. ).
The Academy can accept 1200. They'd like all 2,400, but can only accept 1200.
So...about 500 of the 1200 are principle Noms from a MOC. About 200 are recruited athletes/prep school/LOA. So that leaves about 1,700 well qualified candidates (some 2Q as opposed to 3Q) vying for the remaining 500 slots. The Academy then selects those remaining 500 out of the 1700 to "meet the needs of the Academy" in terms of class makeup in order to best represent our military and our society. In some ways, in many ways, an appointment offer is a lotto ticket.
Be proud if you or your DD/DS made it into the final 2400. That is pretty rarified air.