Why is the Book of Changes so accurate?

The prediction of the Book of Changes or the handed down Book of Changes can only be accurate, because the past that has happened can be counted and found out, as long as there are enough people and the results that have happened as statistical data. If we don't calculate the past, we can't find the so-called laws from the past that has happened (that is, the known), and the predictions in the Book of Changes or the handed down Book of Changes can't speculate on what may happen in the future! Moreover, many examples of "quasi-calculation" that we know (such as "addition and subtraction divination" and "authentic divination") are actually deliberately selected by the author or communicator, and those examples that are not allowed under the same conditions are deliberately omitted by the author or communicator.