Noone's going to deliberately take a kick to the groin. If you get one its because you didn't see it coming in time or you weren't able to move fast enough.
Originally Posted by Hesperus
I suppose someone could incorporate putting their groin into the path of danger as a gameplan, ie. you see a leg kick coming and you move your groin into that area so the other guy takes a foul, sorta like how some guys will drop their hands to the mat when they see a knee coming, or turn their head when they see a punch coming so the back of the head takes it. In this case it may not always be called as a foul though since the blow is not intentional.