http://www.youtube.com/watch?v=qIZXYkY4m7Y
First you need to master the above "Sit up Escape". Once you have that mastered you need to work your way back from the Knot to the Wedge to 1993 position so you can execute the "Sit up Escape"
From the Knot you need to "put on the boot" and hug their top knee toward you. Then limp your not booted leg out and sit up to put yourself into the seated Wedge. With your free arm pull the foot thats in your crotch out, your hand thats hugging their knee then under hooks the same leg and bring his leg over your head and to the other side or your isolated leg, this will bring you right in the 1993 position to execute the sit up escape.
The spinning or "cork screw" escape is great when they are in transition, not so good when they have you in a solid position of control. By limping the leg out of the know and then attmeping to spin just puts you in the wedge (where you can still be finished) or you run into the calf crush.
I have a few counter submissions along the way as well. But alas that is for another time!