Start by telling us one...The problem is that there are too many secrets....just little things...and no one seem to have them all. Some of the best kept secrets are individualized and specific to a style of plays/individual. The game of pool is unique and has no limits so its a hard statement to swallow when you say all the secrets are out...LOL...you probably wouldn't know where to start if you were to try and list all the secrets to this game if that is even possible.
Just because you can find people who don't know it, that doesn't mean it's "a secret".
Pool is pretty obvious.
pj
chgo