I was on my way to bed; so I forgot to finish that point off, sorry.
(That also explains the overall weirdness of the post. LOL)
Anyhoo; effective SD is far more than just learning how to trade various forms of nastiness on the mat; it also includes awareness, preparation and knowledge of the whole concept. It's been said time and time again; the best way to survive an attack is not to be attacked in the first place. That's true; but what's less discussed is how much control the prospective defender has over that aspect.
Regardless of the origin of the attack; the attacker invariably attacks for only one reason: because he thinks he can get away with it. He picks his targets in the same way a pack of wolves do: bypassing the big and strong; concentrating on the weak, sick, etc. AND the isolated.
Effective SD doesn't start when the fight starts, it starts at home; before you leave your house. It's most important aspects are those which are not
taught in a dojo. Things such as: an awareness of things/people/locations around you. Some knowledge of how and where an attack could occur, and the potential risk. (Example: "I'm 5ft. tall, 98lbs and I've got a broken leg. I'm carrying $10,000 in cash in a big green box with dollar signs on it through local gang territory - it'd be a good idea to keep my eyes open.")
An attack doesn't always occur in back alleys, shady areas and nightclub parking lots; there are a great many places - called 'fringe areas
' in which a potential for trouble is increased. "Fringes" are those areas which are public; generally open and seeming safe; but are far enough from safety they could pose a problem. Mall parking lots for example; stairwells, a busy city street where the anonymous nature of the crowd can give a potential attacker the ability to close and escape with a minimum of disclosure. Knowing about these areas and how to protect yourself within them goes a long way towards effective SD.
Once an attacker has made his move; there may still be possibilities of defusing a situation without violence. These have been discussed time and again on this forum. These also
are effective SD techniques not taught during randori.
If the attacker gets through to the final stage, the physical assault; he does so because all the criteria for a potential victim has been met; and all possibilities for non-violent conflict have been exhausted. Then and only then does what is taught in randori come into play, IF the attacker gives you the chance to use it. If you're being mugged; he's NOT going to come straight at your face from twenty feet; he's going to ambush you.
Whoops - I've did it again; rambling too long and dealing to much with specifics; always a danger when writing on this forum.
Let's sum up like this: Full-force randori is an excellent tool for teaching defence of the physical assault; but in order to be truly effective at SD; a student must learn those techniques and concepts which will enable him/her to reduce the risk of attack in the first place.
Hope that clears up my viewpoint on this. Thanx!