The girl on top benefits simply from her position.
Gravity works for her. It constantly holds her opponent down and holds her body on her opponent.
Gravity also accelerates her punches down. In contrast, the pinned girl’s punches are weakened by this force pulling them down even before they are thrown.
The girl on the bottom often tries to sit up, but this is easily thwarted by the other girl pushing her back down or moving further up on her. Her failing attempts tire her neck and stomach muscles.
Being on her back, the bottom girl loses the ability to use her arms to push herself off the ground or to use her legs to raise herself onto her knees. She is similar to a turtle on its back. Arms and legs flail about, without much effect.
These physical handicaps play on her mind. Fear, desperation, and insecurity grow.
She may try to bridge, which involves thrusting her hips up to throw off the top girl. But with inexperienced fighters, this is often aborted after her opponent’s body lunges threateningly towards her head.
The top girl is able to protect her body with her hands and arms better than her opponent. Because her knees and thighs are crowding her opponent’s arm movement, and because the ground further restricts this arm movement, her opponent cannot protect vulnerable areas as well.
But more than just that, the bottom girl’s position acts on the minds of both girls (more on this in psychological advantages chapter). The bottom girl feels more vulnerable, and the top girl feels tougher.
The bottom girl may pretend not to care that she’s pinned, just to psychologically attempt to eliminate the powerlessness of her position. But this mental defense cannot last.
With little effort, the top girl can immobilize her opponent’s arms. She may use her hands to pin them to the ground. Or if she maneuvers her shins over the bottom girl’s arms, she incapacitates them.
She is then free to punch or gouge at the eyes of the other. She can even use the ground as her weapon, slamming the other girl’s head into it.
One or both of the bottom girl’s arms may also be pinned against her own body by her adversary’s thighs or buttocks. The top girl also can wedge the bottom girl’s arms between her calf and thigh, incapacitating them.
Besides these actions restricting arm movement, blood nourishing the arm muscles can decrease. The arteries can be compressed along the inside of her upper arms.
The bottom girl lacks all of these debilitating options. The top girl may even confidently taunt, “Now what?” “What now?” or “What're you gonna do now? Huh?” to emphasize the bottom girl's latest loss of arm motion.
Some girls never imagined that this level of immobility were possible. They are shocked when pinned in this way. It never occurred to them that this totally submissive position could happen to them, and they give up fighting almost immediately.
This freeze response may be a final attempt to stop the top girl from continuing to fight.
The top girl, like a baseball pitcher, can move her fist back behind her head and throw it at the bottom girl's head with more velocity and force. She can use her body to add force to each punch by raising it up and letting it drop down with the punch to add momentum. She can curl her stomach muscles as the punch travels to further increase its strength.
With every punch the top girl throws into the bottom girl, the ground prevents the bottom girl from moving backward. This makes each impact more destructive. In contrast, the top girl can move back with the bottom’s girl’s punches, decreasing the energy of their impact.
If the bottom girl’s arms are not pinned down, both girls have the option to choke each other with their hands. However, the top girl can hold this position better by pinning her adversary’s neck against the ground. She can easily break a choke hold on herself by leaning back or rising on her knees just a few inches.
The bottom girl has some leg movement, but often fails to utilize this to any advantage.
Her head movement is blocked from behind and may be further confined if caught between the top girl’s thighs. This increases her vulnerability to punches to the face, choking, scratches or pokes to the eyes, and hair pulling. Head movement may also be compromised if the top girl’s knees rest on the other girl’s hair.
In a play fight, the top girl may use her hands to try to close the bottom girl’s nose and mouth to playfully tease her vulnerability. In a serious fight, the top girl may stuff mud into these orifices or hit them with a rock. If a puddle is nearby, she may push the bottom girl’s nose underneath it. Or if an object is pushed into the bottom girl’s mouth and touches her uvula, she may reflexively vomit and fear drowning or choking in this vomit.
Her clothes may be ripped or pulled, revealing private parts to bystanders and causing humiliation. The bottom girl lacks physical freedom, making it more difficult to prevent this and to reciprocate this on her opponent.
If she wears a skirt, she is already in a revealing position and subject to humiliation and jeers from the crowd. This is another difference between girl versus guy fights. Also, girls have two private areas which can be revealed versus guys’ single private area.
The front of a person is more offensive. It includes unobstructed facial language, eye-contact, verbal comments, body odors, and greater capacity for violence.
Steadily facing someone with eye contact is rarely accidental. It is usually made to either establish dominance or communication. You can see the dominance component play throughout the animal kingdom. But these two fighting girls are not interested in friendly communication. More of the top girl's front is unobstructed than the bottom girl's.
This dominant front psychologically attacks the bottom girl.
Facial language from the top girl of confidence, smug superiority, and calm demeanor communicate success. The top girl’s facial language, eye-contact, and verbal threats have greater impact because of her dominant position.
If the bottom girl shows confidence, makes eye contact, or makes verbal threats, they are not backed with real power. They are laughable and more likely to be dismissed.
If other people are around, the bottom girl is more vulnerable if one of them decides to attack, because then she will have to deal with the top girl and this other person. Her head could be easily stomped on by a bystander. A friend of the top girl could easily help keep the bottom girl pinned so that the top girl has more freedom to land punches, pull hair, scratch eyes, poke eyes, choke, or create other major damage in a very short amount of time.
But a friend of the bottom girl would first have to unseat the top girl, and then pin her down before she could be attacked as effectively. By this time, a comrade of the top girl could intervene to even the odds.