Explaining how Batman works written is a huge task. There is simply so much Batman. Since the character's creation in 1939 every conceivable tone has been struck with these stories. And if every twist or variation hasn't been tried, well, almost all of them had. You can read a Batman story in an alternate D.C. Universe where Bruce Wayne marries Selena Kyle and has a kid. That's not fanfic, that's a D.C. imprint from the 80's I think.
Really enjoyed this subject. As a child, I was always fascinated with his detective skills.