What's your definition of "your opponent's center"?It is about attacking through the opponents center... If you attack up the center I attack through your attack toward you center. I do not go around your arms. I do not need to open your guard to attack you.
Is it his front door (space between his arms)? Can you attack your opponent's center through the side doors (space outside of both arms)?
How do you attack your opponent's center without dealing with his arms if he has "rhino guard"?