Just one more comment and then I'm out of the discussion.
Again I'm not arguing the merits of Dr. D's system. I believe it works.
BTW, it is not "my system" (except for the peace-sign stuff and the 0.281 marked-cue RCA stuff). Coriolis discovered the 2/7 RCA system in the early 1800s, Bob Jewett came up with the cue approach, and Patrick Johnson came up with the CB-tangent-line-drop approach.
I'm not saying the method in Hoppe's book is better or worse.
In terms of giving an accurate carom direction, the "back of the ball" system is most definitely worse.
I do think, with any system, (disregarding fundamentals errors) practice and experimentation is needed to perfect, if perfection is even possible.
I'm confident the math is accurate. Dr. D wouldn't publish it unless this is so.
Agreed. With enough practice and "adjustments," any system can be made to be very effective.
That said, the method in Hoppe's book works within certain range of attack angles. Other angles requires practice. Some angles, ?? Well ya gotta go with another method, or game strategy. I know this and this topic has nothing to do with my original question.
I suppose there's no answer.
The "back of the ball" system does give the correct line at one angle (close to a 3/4-ball hit), and comes close with fairly full hits (close to and thicker than 3/4-ball hits), but it is not as good as other systems, unless you "practice" enough to develop "intuition" for how to correct for the inaccuracies when necessary.