See class, in self-defense, the gender of your opponent matters.

A single kick to the crotch to a male is enough to completely incapacitate him. As we just saw with Jerry, who’s still rolled up in the corner.

But as you can see, a female is able to withstand multiple kicks to the crotch without any signs of damage. 

So before you fight, quickly survey the genders of your opponents in a real fight. Knowing who the males are puts you at a significant advantage. A crotch kick is a tactic that works against boys, but not against girls.