The most advantageous position you can get from closed guard is when you manage to get your opponent’s hand across the centerline.
This position enables you to enter into series of attacks from which, if done properly, there is no good option for your opponent.
You will either manage to sweep the opponent (getting into full mount position), attack the arm lock on the trapped arm or attack the opponent back from the back mount.
3 Main options when you manage to get the elbow across the centerline