The book "Liao Fan's Four Lessons - A Classic Work About How to Change One's Destiny" is an insightful book. The entire book has been translated and can be found in this website:
The high accuracy of Destiny Reading is very much exaggerated in the beginning of the story. In the end, the hero of the story changed his destiny by his good deeds and the accuracy became 0.
The moral of the story is:
Destiny Reading can be highly accurate but we can change our destiny to make all predictions highly inaccurate. Therefore, the art of Destiny Reading is to advice people how to live a meaningful life within certain limits. A good astrologer can predict accurately your path of life according to your natal chart. A better astrologer can advise you how to make the prediction inaccurate to your favour.