A ground position where the top fighter sits on the chest of the bottom fighter with his knees on the ground on either side of the bottom fighter's torso, the mount is one of the dominant positions in ground fighting. The bottom fighter's legs are for the most part taken away from him and he has only his upper body to defend himself. A trained fighter has more ability to use his full body when on the bottom of the mount, but has basically no offense.
From mount the top fighter can strike to the face with punches, while the bottom fighter will not be able to reach the top fighter's head.
In MMA or self-defense situations this gives the top fighter significant advantages, he can strike and choke with the advantage of gravity, while the bottom fighter is fighting against it. In a self-defense situation the top fighter's groin is exposed, but any attempt to attack there leaves the bottom fighter's eyes, face, and neck exposed to an attack.
What surprises many novice grapplers is how difficult the mount is to maintain, even against other novices. So in grappling classes when the mount is first taught, the focus of that initial lesson is often controlling and maintaining the mount.
The first control drills are often hand fighting to stop untrained fighters from using their arms to muscle the top fighter off. The top fighter uses a variety of grip fighting movements to keep the bottom fighter from being able to push against the top fighter's chest, hips, or legs. The top fighter will also plant his hands on the mat for extra base and to keep his legs from getting trapped to prevent being rolled over.
Here is Rorion Gracie demonstrating the basics of this kind of mount control:
Now it is important to note that this is geared towards controlling a fighter not trained in escaping the mount position. A trained fighter will make better use of his legs when defending this position. The bottom fighter can use the buck-and-roll escape or the knee-to-elbow escape that have been covered in previous Bloody Basics articles, and it takes a different kind of defense to prevent those escapes.
Stopping or weakening the bridge of the bottom fighter is one of the keys to controlling the mount. One way to do that is for the top fighter to adopt a low posture and spread his hands on the mat for base, to keep from being off balanced by a bridge. Another trick is for the top fighter to use his legs to entangle the bottom fighter's legs and hook under the bottom fighter's head, lifting it slightly off the mat, greatly reducing the power of the buck. And if all else fails the top fighter can quickly raise his hips and move to what is referred to as modified mount instead of trying to fight the buck.
Here is Ralek Gracie nicely demonstrating those techniques
Now that is not the only method to shutting down the buck from mount; there is also what is referred to as the "high mount". This is achieved when the top fighter slides his knees into the arm pits of the bottom fighter and rests his hips on the bottom man's chest, greatly reducing the power of the buck from the bottom fighter.
It is a very powerful position and here is master of all things mount, Roger Gracie, demonstrating the basics of the high mount and an armbar attack from there.
Sometimes, however, in spite of all controls used the top fighter is going to lose the mount as the bottom fighter goes to buck over, it is at that point that the top fighter must win the transition and take the back. Similar to moving from the modified mount which was shown above, the taking of the back involves taking pressure off the bottom fighter and allowing them to roll, and positioning the legs as they move.
To demonstrate the technique here is Professor Young of Champions Jiu Jitsu in Texas, now a black belt under Carlos Machado and a retired police officer. He also gives us a bonus technique of how to move back to the mount from the back.
So that is the Bloody Basics of controlling the mount, and once a fighter has mastered that there are a variety of attacks from the position. To end with, here is Saulo Ribeiro, BJJ legend, and UFC Welterweight Champion Georges St. Pierre teaching a variations on the armbar from mount.