Asides that, every other game is based on luck and there is absolutely no way to guarantee winning unless one is just fortunate enough than every other person in the casino at that point in time. In one word, there is no way to win in gambling.
If someone is thinking like, has found a way to win will only put one into an emotional situation when it comes to gambling because, such a person will tend to over rely on such way, and when things are going wrong, rather than stopping, they just will want to push themselves harder the more. Winning is a lot dependent on luck, and not thinking about it too much and letting it come more as a surprise is always better for any gambler as that will make you appreciate your winning if you eventually do win.
Yes, totally agree, I didn't factor-in confidence when I was criticizing positive thinking because I was thinking only about luck-based games. Obviously, when you are playing poker or any other skill-based game, the confidence is an important factor (and skill is the other important factor, maybe even more important - you can be all-positive-thinking, but if you lack skill, you are bound to lose)