I have learned this lesson the hard way, but the reality is no. The reason why is your average person who wants to hurt you is not going to make their intentions known or will act when they know you are not expecting it. I have found that for the most part training helps you in damage reduction, it has probably saved my life once or twice since drunk people tend to not know when to stop. Have I put them into positions where 'I won' the fight? Sure. Did I feel like it? Nope, the bruises, cuts, etc still make you feel like you got your ass kicked.
I'm not saying it isn't worth it, it totally is, I am saying that it is better to understand what your training will really help you with in the real world. It helps me stop friends because I know how to properly hold them back/down, it helps me understand what is going on under duress, and it helps me keep in shape and challenge me. It does not stop a kid with a baseball bat attacking you from no where.
Reread that and it sounds a little depressing, but it is honest.