Is it so important to determine before and after when predicting six strategies? Is there a difference between treating the back as the sun or the front as the sun? Is it just a formality?

Traditional divination takes the back of a coin as the sun, which is effective when you recognize it.

If you want to do the opposite, the hexagrams based on this idea are also effective after being determined in advance. However, when arranging hexagrams, we can no longer determine the yin and yang sides of coins according to the traditional definition, but arrange the plates according to our own defined rules.

In a word, divination won't lie. Divination is like a mirror, which is an objective reflection of things related to you when you are divining. You change, you will change. You are actually deceiving yourself.