As a full professor in a well respected department I got paid pretty darn well for what I did. I would tell you everything I know and then give you books, and leads on the most current information. My colleagues over a period of 25 years in the teaching profession were no different. It seems to me that this is what teaching is about. A "real" teacher's life is about service to others in the pursuit of the truth. In the past I have been responsible for hiring and furthering the education of many teachers and potential teachers.
Seems to me that if a pool instructor is a house pro they are being paid to teach others and should be a teacher in the sense I have outlined above. If they are not a house pro or do not have their own house, they are probably not much of a teacher.
A person who has a sufficient amount of information that will help others learn often places it in a book or on a DVD. Joe Villalpando "free lances." and does a darn good job of it with his instructional materials. Freddy the Beard and Dave Sapolis are apparently among several others who teach well one on one. These "coaches" are often better than a teacher based on their particular style. (I do not personally know any of the people referenced here).
Others who solicit students may need to make a living. None-the-less a teacher, by definition, is willing to share what ever they know with whoever asks and generally speaking in whatever format, Internet, correspondence, live interactions. That is what it means to be a teacher. Based on comments made by the teacher, students will often, not always, seek out their instruction because they have learned that the teacher is willing to share everything and that often times techniques are best learned face to face.
Good teachers have learned that for every potential student who does not come to them, five others will at the end of the day. The student who learns "for free" tells all of his friends and acquaintances that the teacher is great, though they could not afford the service.
I would suggest that people who do not proceed in this manner are not teachers. They are doing something else.
I suspect there are no secrets, but there are some excellent teachers and coaches. If there was a secret, there are simply too many excellent teachers and they would have revealed it.
If there was a secret, Dr Dave has probably already published it. He too comes from the same environment.
