The best way to "calculate your chances" is just to take care of your stuff. Only you can control just how attractive you make your application for a pilot slot, so it's up to the individual to take care of business. My advice would be to major in something that you want to do, not something you think you have to do -- a lot of guys who say that they want aviation in my unit have automatically assumed that they have to be aerospace engineering majors if they want aviation, which just isn't the case; their grades have suffered because they are either not willing or not capable of doing well in their classes. I chose political science as my major because it interests me and I know I can do well in it. It would also be my advice to educate yourself as MUCH as possible about Naval Aviation and aviation in general before you get set on it. Too many people in my unit say they want aviation, yet have no clue about flying and Naval Aviation at all. They watched the movie Top Gun once and decided that they were gonna be God's gift to Naval Aviation. If your conception of Naval Aviation comes from the movie Top Gun, you are sadly mistaken. American military aviation -- especially Naval Aviation -- is the most professional cadre of aviators in the world, just ask any aviator on this forum. The more you know, and the more you can educate yourself, the better.