Is Yuan Tiangang's fortune-telling credible?

Is Yuan Tiangang, a theologian in Tang Dynasty, accurate in fortune-telling?

The sage of Yuan Tiangang is not a theologian, but can be called an astrologer, Ibrahimovic or a magician. This person and Li are also called two immortals, which have the mystery of reaching the yin and yang of heaven and earth and the unpredictable chance of ghosts and gods.

The so-called fortune-telling method is called Yuan Tiangang's "physiognomy", which is a fallacy circulating among the people, but the real formula is only in the hands of future generations, not the "addition and subtraction arithmetic method" contained in the almanac.