In case anyone is interested in what the science community has to say about CTE, the following is a clip taken from Dr. Daves site. If someone wants to know a little bit about the background of Hal Houle and CTE, here is a very good article by Roger Long:
Another graph and full version of Daves article can be read here:
Billiards and Pool Aiming FAQs
Here are a couple of graphs of the CTE pivot distance (from the tip) according to the desired cut angle. The colors lost something in translation, so some description is in order. The middle curve (black) of the five in each plot is the correct pivot distance for the desired cut angle on the bottom axis. The two adjacent curves, one above and one below, each show the pivot distance that would result in a 2 degree error in OB direction (4 deg. total range). The outermost curves show the same for 5 degree errors (10 deg. total range).
The curves were generated according to the description of the method described at Spiderweb's (Dave's) blog. Based on the somewhat complex shape of the curves, it's hard to see how anyone could know the right pivot distance, or get away with using only one or two. Moreover, in the range of about 20 to 40 degree cuts, the pivot location moves beyond the end of the cue, approaching infinity as you near 30 degrees.
(Also keep in mind that systems are based on one contact point on an object ball, while in fact the ideal contact point changes with any spin applied.)
More from Dr. Dave:
With all pivot-based aiming methods, the choice for "effective pivot length" must vary with the distance between the CB and OB, as illustrated by the following diagram from my November '08 BD article. Note - the purpose for this diagram is simply to illustrate a general principle pertinent to all align-and-pivot systems like CTE and 90/90. The diagram is not meant to show a specific aiming example for any particular system or shot. The pre-pivot alignment shown is actually a 90/90 edge-to-edge (ETE) alignment, but again, this choice is not important to the point being made. With a fixed alignment (whatever alignment that might be) and a fixed "effective pivot length," the distance between the CB and OB has a huge effect on the resulting cut angle of the shot:
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