Yet again this has become a very complex thread with many different subjects being debated under one thread.
1) Judo in 2013 is a sport. Practiced by the vast majority as a sport. To that end learning judo as a self defence is not the wisest way to learn a self defence.
2) We need to define what we mean by self defence. SD in terms of a professional soldier, police officer, security guard, general adult public, children, office workers, office executives etc, the list is endless. SD for each of these groups differ.
3) I do not believe now nor ever have believed self defence can be taught and learned by a population as a whole. By that I mean there is not one SD to fit ALL GROUPS OF PEOPLE.
4) SD in relation to most physical combat activities is no guarantee that the person will be able to become proficient in SD in terms of a street attack. I will write again SD is much more about the person and his character than the combat system he or she chooses to learn.
5) Some combat activities may well prove more effective than others no doubt about it and I am NOT going to get into a dick measuring contest about whose system is best.
6) CK sensei mentions a world class female judoka would be able to defend her self. I agree with some additions. The character of any world champion is the type of character who excels in self determination, concentration, observation and is highly competitive and does not shy away from a challenge. Add to this the time and dedication needed to study to a world championship level and even a top swimmer would be far better at SD that Joe public.
7) Define what type of SD is needed. What circumstances is one likely to need to defend oneself.

Where one lives, ones country, ones neighbourhood and ones culture will all help toward gearing to asses the needs of ones self protection. In Europe we don't need to worry to much about guns, in the Americas this is not the case. IN some EU countries there is a culture of using a knife in others this is not the case.
9) What are we defending? If a person is walking down a road and an attacker askes for his wallet or her handbag. Give it every time and walk away. This is not generally the way modern attackers operate. PLEASE remember this vital factor. Most mugging or street attack is not spontaneous. The attacker will have watched his victim, prepared the time and spot to attack and attack from the rear NOT the front.
The attacker will have made mental and physical preparation for the attack. The victim while walking home may be thinking about what's for dinner being totally unprepared. Now the unprepared victim is at a grave disadvantage. panic, the flight and run syndrome or the curl up into a ball and pretend its not happening syndrome, rabbit or hedgehog. Ones heart rate rises to the point of hyperventilation causing some to feint, wet themselves or dirty soil the underwear. Most shake and most panic with a massive rush of adrenaline causing all sorts of psychological effects not to mention the physical ones. There is not QUICK FIX FOR THIS. The practitioner of some full combat arts will be better at control than others, many will react in the same way.
The street is not a dojo and the attacker is not going to rei wait for hajime, take hold and fight for grips.
The speed and devastation of being attacked in the street is not an experience most human beings deal with very well. Forget the cinema. The cinema is entertainment.
10)A child walking home from school on his or her own is a victim. Period.
11) Most average people walking home from work are victims. Not even great masters of martial arts are infallible. Street crime is not play, cant be treated like play and is very VERY difficult to prepare some one against.
I am aware of these situations due to two significant situations. A) In my professional capacity I have counselled, either as individuals or in groups, adults and children who have been attacked or harmed. B) I have taught troops SD for over 20 years and received vital feedback from those who, thank heavens, returned after going into an LZ.
I have refused to teach
courses in SD to the police, prison service, women's guilds, victims of rape. The list is wide and varied.
I HAVE agreed to give lectures on SD and self preservation to all those groups and I have agreed to teach SD and restraining techniques to law enforcement officers providing these courses where lengthy and before a member stopped they passed a small test.
I find it highly irresponsible to teach judo as a self defence. I find it just as irresponsible to teach courses to the public in SD. To me it is often going to give the pupil a false sense of confidence where said pupil will not take care of themselves and some will actually go into situations knowing there is danger with a sort of morbid idea of try me out! Fatal. I wont be a part of it.
Can judo waza be used in a SD situation. Yes. How long would that training take? No idea but certainly many many years. Is there a more effective manner of learning an SD than Judo? Yes. Does learning
any system of SD mean one is safe or even safer, not necessarily. So many factors need to be taken into careful understanding.
Massive subject.
Mike