Read this blog with interest. While I can see some merit in what Tiny is saying I feel that no matter how you train or develop your skill level there is always someone fitter, faster , bigger and nastier than you around the corner. The trick is to avoid meeting him/or when you do recognize the situation.
I think Aikido can assist you in judging situations. Body language for example cab influence the situation in a positive /negative manner.
As for unprovoked attacks , even the best prepared guy cannot do too much against this type of offense.
All we can do I think is keep our wits about us, use common sense and if push comes to shove , do the best we can and hope the outcome favours us.
You have it Joe!!
That is good common sense....