In a streetfight you have to do everything possible to protect yourself and or family. Biting,hairpulling eye gouging even cheap shots that you would never do when sparring in the dojo with your friends. When someone wants to kill or rob you then you might end up fighting to the death because its hurt him before he hurts you. Granted this information is coming from a 17 year old who has been in fights but can handle them without going to the seriousness thats involved in a true streetfight.