Asking a CTE user for a clear explanation of the system is a waste of time?
"Clear" is obviously not working for you Pat, that has been done here for years, so let's try it a different way.
"Simple Explanation" of CTE. The method of seeing a cue ball and object ball together with regard to their position on a 2 x 1 pool table, from a certain visual position.
There, now that is pretty simple, wouldn't you agree?
Now the fact that no two peoples vision is exactly the same must come into play, because even though the balls and the table look the same to everybody, the way they see or perceive them may, and likely does, vary, but then we know that, for sure, because people have different ways of aiming and always have.
You can choose to guess where to aim and eventually find a point of aim that feels right, and then you may or may not even make the shot based on that feeling. That doesn't make that method any better or any worse than using a method that takes that guesswork, or waiting for that feeling, out of the equasion, and just shooting when you see the shot alignment a cetain way. That is what the CTE system attempts to do, provide a visual that is repeatable that can be used on most any shot, without the need to feel that you are in fact aimed at the contact point, or even considering the contact point in the process at all.
BC21's does basically the same thing, I bought his book when it first came out and I can't remember feel or contact point being mentioned in it to determine the aim line of any given shot. So what is the difference? They all eventually arrive at the contact point if they result in making the ball, but that certainly doesn't mean that feel was necessary in the process.
I have read a lot of things you have written over the years about various billiards related topics and have no doubt you are very knowledgeable on the subject, and so it's amazing to me how close minded you are when it comes to the subject of aiming, specifically, aiming with the CTE method. If, by chance you are basing your opinion of CTE on the method Dr Dave has posted then that is a little bit understandable because he obviously doesn't understand it, or explains it very poorly at least. I would hope that given some of the writings you have done, you would do the research and form your own opinion of CTE rather than just go by hearsay. I would hope your other writings and opinions are truly your own.
Regarding Cad and CTE, drawing 2 pool balls on a flat surface is about the easiest thing in the world to draw. Adding a third object, such as a pocket, still pretty easy. Drawing a line from the center of the pocket through the center of one of the balls, say the object ball, still not complicated. Drawing a 3rd circle centered on that line tangent to the object ball easily and perfectly identifies the contact point. We can call the 3rd ball ghost if you like. So drawing a line from the center of the ghost ball through the center of the remaining circle, cue ball, represents the line of aim to perfectly strike the object ball with the cue ball to arrive at the center of the ghost ball, coincidentally at the contact point, which finally, drives the object ball into the pocket. Simple enough, yes? So that is all you need to know then right? NOPE! While all of this is mathematically perfect, every time it happens is a unique circumstance based on where the pool players vision center is when they perform the task. The shot looks slightly different to every player, and even varies slightly every time it is approached even by the same player. So, most aiming systems bring the player up to this point, which rightfully so, does perfectly describe what needs to happen to make a basic cut shot. But suppose we add 2 more pieces of geometry into the example for this shot. Lets make them say 2 circles, about 1 inch in diameter each, space them say 2 3/4" apart center to center, link them together so they move in unison and the place them spatially relative to the flat plane of the pool table say, 32" back basically along the line drawn between the ghost ball center and the cue ball center, and say 18" vertically above the plane of the pool table. This we will call shot position. Oh yeah, let's call these last 2 objects EYES. Now we know so far that the shot earlier described is mathematically perfect; Imagine the eyes being yours and you are looking through them at the balls and the pocket layed out in this example. It is still perfect, YES? Now move your head, just a little, any direction, and look at the shot. Looks different right? BUT, is it still perfect? Why yes, yes it is. This is the point.
This is why I will never, ever make a CAD drawing explaining it. It is different for every shot, for every person, every time, and mathematically correct every time. Repeatedly asking for such a thing is a very profound declaration that the asker has no clue what he is asking for. Every example drawn would look almost exactly the same to the learned user and would mean absolutely nothing to anyone who doesn't understand,,,,,,,, a giant waste of my time.
CTE is simply a method, a step by step process, to train the user to systematically approach shots in a repeatable manner of seeing the same thing from shot to shot to shot.