Yuanhai Zeping (渊海子平)

Yuanhai Zeping (渊海子平, "The Deep Ocean of Zeping") is the oldest and most foundational text in the BaZi tradition. Compiled in the Song dynasty and attributed to Xu Ziping (徐子平, c. 900–1000 CE) — the scholar after whom the entire BaZi system is sometimes called Ziping methodology — it established the core framework that all subsequent BaZi texts build upon.

Xu Ziping and the Ziping Revolution

Before Xu Ziping, Chinese fate calculation centred on the year pillar — the annual stem and branch as the primary indicator of a person's destiny. Xu Ziping's pivotal contribution was to shift the primary focus to the day pillar and, specifically, the Day Master (日主). This reorientation — from year-based to Day Master-centred analysis — is the defining characteristic of Ziping BaZi and remains the foundation of all modern Four Pillars reading.

Contents of the Text

Yuanhai Zeping is an encyclopedic compilation covering:

• The Ten Heavenly Stems and Twelve Earthly Branches — their elemental natures, yin-yang polarity and seasonal relationships
• The Four Pillars — how to calculate and interpret the year, month, day and hour pillars
• The Ten Gods — the earliest systematic exposition of the Shi Shen system, relating each stem to the Day Master
• Special Formations — a catalogue of named chart patterns (格局, gé jú) that indicated specific life outcomes
• Life theme readings — sections on wealth, career, marriage, children, longevity and travel
• Shen Sha — a large compendium of divine indicators and symbolic stars

The Formation Approach

One of Yuanhai Zeping's distinctive features is its Formation System (格局法, gé jú fǎ). Rather than reading the chart purely through element balance and useful god, it identifies specific named formations based on the month stem or branch and the composition of the other pillars. Formations like "Zheng Guan" (pure officer), "Shi Shen" (eating god formation), or "Jianlu" (sword-edge formation) carry their own named characteristics and outcomes.

The formation approach and the useful-god approach (from Di Tian Sui) represent two major schools within classical BaZi theory, and most modern practitioners draw on both.

Historical Significance

Yuanhai Zeping is the root text from which all subsequent BaZi works derive. Di Tian Sui, Qianli Minggao, Sanming Tonghui, and every other classical text either explicitly comments on Yuanhai Zeping or implicitly builds on its framework. For a serious student of BaZi, understanding Yuanhai Zeping is essential for understanding why the system is constructed the way it is.