The main issue is how to apply it in actual operation. First, conduct historical verification on the varieties you are familiar with according to the rules, calculate the probability of winning under various circumstances, and calculate your position based on this condition. Doubts about a rule mainly come from the fact that no rule is 100% correct. The key is if this rule suffers a loss, what is the maximum amount you can accept? That is to say, when opening a position, you must calculate the ratio of stop loss and take profit according to the rules, and only operate opportunities that have a high chance of winning for you and a large return ratio. You have to give up a lot of things. This is a psychological problem, not a problem with the rules. .