What’s the difference between Four-Pillar (Zi Ping) and the Three-Life (Sanming) systems?

Zi Ping (Four-Pillar) and the older Three-Life (Sanming or Na-Yin) system represent two major historical stages in Chinese fate theory, and they differ fundamentally in philosophy, core methods, and analytical emphasis.

Detailed differences:
• Three-Life (ancient Na-Yin method):
- Core: Treats the year pillar as the absolute central indicator—the root representing ancestry and innate foundations.
- Five-element basis: Uses the Na-Yin Five-Element classification (for example, Jia-Zi and Yi-Chou assigned to poetic categories like “Gold from the Sea” or “Fire from the Furnace”), a more symbolic and macro layer of five-element interpretation.
- Analytical focus: Emphasizes social origin, family inheritance, and the individual’s resonance with large-scale cosmic cycles. Its methods are relatively archaic and give strong weight to the inherited, pre-given part of fate.
• Four-Pillar (Zi Ping / modern method):
- Core: Centers analysis on the Day Stem (day-master), representing the self.
- Five-element basis: Relies on the standard Five-Element attributes of stems and branches, and on their cycles of generation, control and transformation, plus combined relationships (clashes, combinations), allowing finer, logical analysis.
- Analytical focus: Concentrates on the individual—assessing the day-master’s strength/weakness, the Ten-God relationships formed by the other seven characters, and the overall configuration (e.g., wealth-officials, resource cycles). It emphasizes how luck (yun) modulates innate tendencies.

Modern usage: Zi Ping is the mainstream approach today. Na-Yin remains as a supplementary reference for certain symbolic readings (temperament, imagery) and for things like compatibility, enriching the interpretive palette.