I grew up as an abused child, I was an outcast who turned into a scrapper in school and my first marriage had some serious ugliness. I've taken a lot of hits to the face/head in my time, hard enough that I have had at least three black eyes, and I've never been knocked out. Because knocking out a woman is pretty much the same as knocking out a guy, you have to know how to hit, and they have to be the kind of person who goes down from that sort of hit.
Street fights have a lot of shit that go into them, you don't know how things will play out and hypothesizing is a fools game. There's technical skill, strength/height/weight ratios and then the unknown factor, i.e., who is crazier.
In self defense courses one of the biggest hurdles they have to first overcome is getting women beyond the whole "it's not ladylike to fight" mentality. Then there's fear, which literally freezes people, both men and women, when confronted with a life/death situation.
Now, back to Africa. In that country women are taught to be submissive, which turns them into easy victims. In this country, woman can learn to stand up for themselves and whenever a woman fights back they have a better than 50% chance of getting away because they aren't such easy prey (that's why self defense classes work).