One of the first things they taught us in TKD when we're in our bull sessions about street self defense is to NOT rely on crotch kicks. You think they'd hurt, but when you're in a fight, you don't even notice it.
I've been accidentally kicked firmly in the crotch while sparring, and I barely notice it. LATER, after the bout when the excitement cools down, I start to hurt. That doesn't help you any.
You want to make someone notice, punch/jab/backfist them in the throat (front or sides of throat). Unless you train a fair amount to hit nerve centers, the throat is the biggest, easiest, most vulnerable spot on the body. You whack someone in the throat they WILL be hurting.
A hard backfist to the side of the throat will drop a man for minutes if you connect well.
Also, you don't pull punches. Someone attacks you, you respond with as much violence as you can muster until you're sure you can get away, then you get the hell out as fast as you can.
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