Came across this article. Thought it would be a good discussion! 
Link
CKF: What do you think of the empty hand knife self-defense techniques in the Parker system (raining lance, glancing lance, thrusting lance, entwined lance and piercing lance)?
MR. PICK: My experience with learning the knife techniques from Ed Parker was different than how I do those five basic techniques. I believe those five are as is the early learning forms, basic concepts, theories and principlesĀangle changes through rotational action, rotational angular deviation, trapping, working on the top side of a sphere and attacking the attack. For Glancing Lance, I believe too much emphasis is placed upon a circular extended handsword than an attacking line to intercept; the rest of the action should begin to combine multiple actions and remove the isolations. Raining Lance from an overhead attack should be defined in angles instead of the customary putting circles into orbit so these orbits do not re-orbit into yourself. A bracing angle such as the first strike in Dance of Death to the groin locks the arm into the body for the attacking guided arm will be physically plunged into the target; then again targets alter circles and lines, these being simple methods of target acquisitions. Concepts should be arranged in regards to expanding the domination of the outer rim principle, creating a dominating matrix.

Link
CKF: What do you think of the empty hand knife self-defense techniques in the Parker system (raining lance, glancing lance, thrusting lance, entwined lance and piercing lance)?
MR. PICK: My experience with learning the knife techniques from Ed Parker was different than how I do those five basic techniques. I believe those five are as is the early learning forms, basic concepts, theories and principlesĀangle changes through rotational action, rotational angular deviation, trapping, working on the top side of a sphere and attacking the attack. For Glancing Lance, I believe too much emphasis is placed upon a circular extended handsword than an attacking line to intercept; the rest of the action should begin to combine multiple actions and remove the isolations. Raining Lance from an overhead attack should be defined in angles instead of the customary putting circles into orbit so these orbits do not re-orbit into yourself. A bracing angle such as the first strike in Dance of Death to the groin locks the arm into the body for the attacking guided arm will be physically plunged into the target; then again targets alter circles and lines, these being simple methods of target acquisitions. Concepts should be arranged in regards to expanding the domination of the outer rim principle, creating a dominating matrix.