The contest is pretty simple. Two women stand next to each other and take turns punching each other with their bare fists until one gives up. A woman may retire one breast if she feels she can't take any more punishment there, which means all the rest of her opponent's punches will have to be to her other breast. If a punch knocks a fighter down her opponent will be allowed three additional punches, and these can be anywhere (belly, face, or to a previously retired breast) in an attempt to knock her out and win the fight. The punches can be delivered on the ground or after the girl stands back up. A fighter is allowed 15 seconds after being hit to recover from the blow and return fire, or her opponent will be allowed to hit her again. The fight ends when one woman gives up or is knocked out.
So the question is what is the best way to win? I'm thinking using closed fists which would give the most powerful punch and knocking your opponent down gives you a decided advantage with the three extra punches. However, anything is allowed, including keeping your fingers straight so the nails (no restriction on fingernail length, other than no artificial nails allowed) can open cuts. My girl thinks making a fist with your thumb extended through the fingers will work best. Then the thumbnail can inflict damage while the breast receives the impact caused by the fist.
Also, do you concentrate on one breast, or spread your attack between them? Do you always go straight for the nipple, or will an uppercut work better? (There's quite a bit of money which will go to the winner, so my girl really wants to win).