Full Mount

From FightWiki

This position can be obtained after getting through the initial Full Guard. It is probably easiest to obtain from Side Control. Using perfect timing and the Knee-On-Belly approach, it is a sure thing. This is the polar opposite of the Full Guard. In Full Guard you are on your back with your knees around your opponent's torso, here you are sitting upright on your knees with all of the body weight on his sternum making it hard for him to move. Be sure not to get too high or you can be "bucked" off, or sweeped; and don't get too low or your opponent may slip his legs out and retain guard. Most fights that come to this position usually end in this position. It is just so brutal and very hard to get out of.