Lol interesting thread.
If folks believe that self defence is about dirty tricks or that one can't train for it, well all I can say is - Good Luck and I hope you NEVER get attacked.
Situational awareness and not making oneself an easy target is paramount to effective self defence (which is part of safety education imho, like learning too safely cross the street) and is the basis of one's "long-medium range" SD system imho. If one truly understands the process whereby attackers target and select their victims and how they interview their targets to "feel them out", then one can act in ways to negate or avoid those conditions, thereby greatly reducing the possibility of physical confrontation. This is the first step.
In situations where we do something stupid and put ourselves into dangerous situations, or attackers are just too stupid to realise that they picked the wrong target or are intent on attacking regardless of warning signs, again awareness comes into play and more importantly our ability to control our fear and adrenal responses in the face of this sort of pressure and danger. Again, these things are part of every physical confrontation, so the key is to obtain a deep understanding of the common factors of a physical attack and maximise one's ability to influence or control these factors.
The ambush/multiple attacker situation (something I've experienced and survived) is probably one of the worst and hardest to defend against, but instead of assuming that I'd be toast in such a situation and immediately start preparing for the inevitable trip to the other side, it may help one to have the presence of mind to at least try to make the best of a bad situation. Training, confidence, calmness and awareness greatly helps your odds when this happens. The whole point of being a victim is that you allow yourself to be violated. Acting contrary to that impression in a powerful manner can have a great effect towards shifting the scales in your favour.
When it comes down to it one needs to realise that the majority of situations will involve some manifestation of a "bully" type attack, whether it be a mugger, rapist etc. and just like a bully, if you mount a fast, effective and petrifyingly devastating attack, they will decide attacking is too much trouble and seek to escape alive themselves. For the others like the mentally ill, sociopaths, those under the influence of drugs and anyone else who generally has left the world of rational reasoning, then Nike Defence is the best imo. Run like hell.
It is very possible to train for violent assault, but one needs a teacher first who truly understands the nature of violent assault, the criminal/sociopath mind and the mind of the typical victim. In the end your particular environment will determine what sort of assaults you may commonly encounter and the types of weapons involved, but nothing is absolutely guaranteed. All one can do is prepare oneself as best as possible and what style or system one does is less important than one's ability to use awareness and function correctly under the intense stress of violent assault imho.
As far as the mindset required for truly entering this realm of training, I think this article may have some bearing imho - http://hobbes.ncsa.uiuc.edu/onsheepw...sheepdogs.html
Of course I reserve the right to be wrong.