Are you being actively recruited by HYP? If not, your chances would be the same as any applicant with similar qualifications. If you are, then plenty of good advice upthread on what you should be considering. If not, take your bird in hand with Stanford. Financially, you might be better off at HYP than Stanford even with an athletic scholarship. Your dad needs to work with the Stanford coach on what your net price will be after the athletic scholarship and need based aid. He can run the NPC for HYP to get an idea of net price there. Your athletic scholarship is subject to loss if you choose or cannot play, but Stanford need based aid could kick in to make up for it.