I'm an advocate of getting your retaliation in first, at the first signs that someone intends to hit you. No point in waiting to get hit before you act. Bullies are wary of kids who hit back because they are fearful of the humiliation that comes from getting beat. So they go for the line of least resistance - the kids that don't hit back. A lesson I learned in my first two years in school. Even if you lose it is still worth the effort, as a bully doesn't want to put the work in, they will avoid you. I've never been inside a jail, but I understand that the same rule applies if you are incarcerated?