As I thought it would this thread got interesting! Some preconceived ideas, I recognize them well because at one time or another I have had most or all of them. Before getting to the heart of things I need to mention everything electronic at my home is giving trouble, probably a massive surge. Computer, router, modem, all flaky. Computer is dying, I'm looking now. Anyway, I just didn't want to give the appearance of hit and run if I disappeared.
Fun facts, I discovered when I was out of stroke I hit a gnat's ass(scientific term) left and about an eighth inch high of where I mean to. This led me to wonder about other people and I put it to the test without saying what I was doing. Just set up a moderately hard shot and told them where I wanted them to hit the cue ball. Everyone, about twenty players from C to shortstop or A at the hall, was very consistent about how far off target they were, and all but two were off target! One was a C- player, the other a banger that played a few times a year. The difference, they both looked at the cue ball last! I did for about three weeks once and found it made no difference in my game. Takes awhile to adjust, then no big deal either way.
We need to be aware of the center point of the cue ball, the real center point that always rests directly above the contact point. While we work on the outside of the ball, the relationship that matters is how the hit relates to the contact point of the ball on the table and the center point of the cue ball. When we start relating to these points, we gain a better understanding of shots. Since there is a practically endless variety of shots on a pool table we have to extrapolate from what we know so knowledge is indeed power.
Two errors I have read over and over in this thread is the idea there is something horrible about crossing the centerline of the cueball and that the sweet spot remains the same size. The largest sweet spot is hitting dead center. The further to the edge of the cue ball, the smaller the sweet spot. If we hit with the same margin of error dead center or one tip out, the margin of error will have far more effect one tip out. Once past the centerball sweet spot, the error always has more effect erring to the outside of the cue ball than erring to the inside. Two different sized coins or anything round should make this apparent if there isn't a pool table or software handy.
Another error, there is something horrible about crossing centerline of the cue ball! Seems intuitive, we are getting left or right spin, sounds like opposites. Well, for starters, that biggest sweet spot, a hit a little to one side will probably have zero effect. When it does have an effect the tiny amounts of spin have a small effect. This is easily proven on a table or with software. A hit a sixteenth of an inch either side of center rarely results in a missed ball or missed shape.
CJ, you never have defined TOI or what you mean by it being twist rather than spin. In one thread you seem to say it has an effect on the cue ball, in another you are saying it eliminates one error since touch of inside has the same effect as a center ball hit. Of course this raises some questions since the distance from a touch of inside to center is exactly the same as from center to a touch of inside. You use words very well both verbal and written but you seem to be inconsistent here, I'm sure not deliberately or in an attempt to mislead. Like PJ, I much appreciate having you here. I find myself in disagreement with some things, in agreement with most. One issue is that there is more than one road to Rome, and more than one way to succeed at pool.
When reading your stuff, I try to watch for the little things, almost asides. Angles are the magic to making pool easy but until a person is good enough to get angles it is hard to make them see that. We did once have five distinct pocket areas or zones as you say in those old tables, far right and left, right and left halfway to center, and center. Tighter pockets might have reduced that to three angles, I don't see them as distinctly as I once did. I also understand the value of putting all of your error on one side to make the pocket play bigger. If you know you often miss a shot to one side if you don't make it, it makes sense to aim to barely make the shot in the other side of the pocket.
Congratulations on starting an interesting thread! I do appreciate the dual difficulties in explaining given the limitations of the written word and not wanting to give away the same thing you are selling.
Time for me to go struggle along with my low deflection shaft and centerball for awhile!
Hu