I think it's a bit obsessive and pointless to try to work out one's "odds".
The biggest point to be made here is that the process is far from cut and dry. Stats really don't mean shit. Nobody cares about your GRE and GPA if other applicants are a much better fit for the program. Nobody cares about how famous your letter writers are if they consider your writing sample to be uninteresting and/or underdeveloped. Nobody cares about your publications/institutional prestige if your statement of purpose is blunderous or you don't seem like a good match for the people in the department, both in terms of research and personality (I've talked to people on hiring committees who swore up and down that the person who eventually gets the job is often the person, of the finalists, who got on with the current faculty best -- they're building an intellectual community, and they want people who seem like they'd get along great).
Moreover, I think this obsession about an applicant's "stats" has grown out of the "How exactly does this process work and what exactly do I need to be successful?" mentality, which is, in many aspects, absurd and dangerously obsessive. GPA/GRE/University prestige (and even publications!) give very little, if any, indication that one is a good philosopher; one shows their competency as a philosopher through their writing sample, a well-written statement of purpose, and writing interesting papers and making interesting contributions in classes that your letter-writers will mention. There are too many very gray aspects of consideration that hugely weigh in on the determination of admissions decisions to say that "one is likely or more likely than most to be successful with x, y, and z." As in myriad situations, the attempt to quantify things is not only unhelpful, but also serves to cover up other aspects of the situation that matter quite a lot.
In the fictional words of Albert Camus (taken from my favorite edition of Existential Comics, "The Analytics at the Bar"), "It's more of an art than a science, old boy."