The Protagonist is the main character of the novel. What the protagonist WANTS should be clear from the beginning.
The Antagonist is the character that (usually) represents the PROBLEM of the novel, that which the protagonist must ultimately conquer in order to get what she wants.
Now let's move on to the less obvious.
(For argument sake, let's imagine a hypothetical story where whole chapters are told from the third person POV of either the protagonist or the antagonist.)
The author's job the first time he introduces the protagonist is to make her likable and/or create reader empathy for her, while expressing what she WANTS. This hooks the reader and makes him want to turn the page. But, does this mean the first chapter must open with the protagonist?
What if the PROBLEM in the story is the antagonist's mental breakdown, the backlash of which sends him on a collision course with an unsuspecting stranger (the protagonist)? Can the novel open with the first chapter about the antagonist?
I guess the question I put up for discussion is this: Do you think it's always better to open the novel by introducing the protagonist; or, does every story need its own formula for success, even if that means opening with the antagonist?
Bonus question: Can you think of a book you enjoyed that opened with the antagonist?
Can't wait to read your opinions on this topic!