If someone is practicing 2 hours a day and is making NO progress then they should see a PBIA billiards instructor, I believe vision center is the nastiest flaw in learning billiards, the reason is that when you are lining up a shot, if you are not truly straight you will be imparting english on the shot, you learn how to pocket balls but always with english, the nasty part is when you learn your vision center the shot looks EXACTLY like the one that is wrong, the difference is you are lined up properly now, my vision center is in the corner of my right eye, when I line up shots I have to use the corner of my right eye to see the shot line properly and when I am shooting the shot, it has taken about 8 months for this to be my new normal way of shooting, without this everything I learned didn't work properly, a friend of mine was a sharpshooter in the military, he is right handed but left eye dominant, check out John Morra's story, all I can say is I can't believe the difference it made for me.