The other 10% of good looking girls can be broke down into 2 groups (about 5% each)
The first 5 % will go into the fight but will quit when they are hit with the first punch or when they have blood drawn on them (you usually see the girls panic when there is blood as they are worried about a broken nose, or busted teeth that will detract from their good looks,) or you can get them to quit by showing the watching crowd their undies or even better to expose their breasts.
the other 5 % are good looking girls who are not frightened to get into a fight and are more then capable of holding their own.
Fortunately if you chose to fight a good looking girl chances are they will back down right away of the fight will be very brief