3 Part Technique - Use Collar and Elbow Control to keep the opponent down initially, but drive with your knee if he starts building a base to stand. If the opponent posts further away and keeps himself upright against your drive, back step using your weight to collapse his base. If you are unable to keep the opponent seated, hook behind his leg with your lead foot before he starts to stand. Connect with a control similar to an Ankle pick to keep the opponent seated. Depending on where the opponent's posting arm is, re attempt the previous moves with your new control.