What Bazi Actually Is
Four pillars, eight characters, one birth moment. Bazi uses the same stems and branches as the I-Ching but reads them as a natal chart—not a situational oracle. The system and the three texts that define it.
Four Pillars series, Part 1
The Same Parts, a Different Machine
If you have spent any time with the I-Ching, you already know the raw materials of Bazi. Heavenly Stems (天干): ten of them, five elements in yin and yang pairs. Earthly Branches (地支): twelve, cycling through the zodiac animals, each carrying hidden stems inside. You know the generation cycle—wood feeds fire, fire creates earth, earth bears metal, metal collects water, water nourishes wood. You know the control cycle—water quenches fire, fire melts metal, and so on.
The I-Ching uses these elements to describe a situation. You cast a hexagram, and the stems and branches tell you about the moment you asked—its pressures, its openings, its trajectory. Bazi uses the same elements to describe a person. You record the year, month, day, and hour of birth, and the stems and branches tell you about the life that started at that moment.
The difference is not the vocabulary. It is what the vocabulary is pointed at.
The Four Pillars
A Bazi chart has four columns, called pillars (柱). Each pillar records one unit of time in the Heavenly Stem and Earthly Branch system:
| Pillar | Records | Role |
|---|---|---|
| Year (年柱) | Birth year | Ancestors, early environment |
| Month (月柱) | Birth month | Parents, seasonal strength |
| Day (日柱) | Birth day | The self—the Day Master (日主) |
| Hour (時柱) | Birth hour | Children, late life |
Each pillar has a Heavenly Stem on top and an Earthly Branch on the bottom. Four pillars, two characters each: eight characters total. That is why the system is called 八字—Eight Characters.
The Day Stem is the anchor of the entire chart. It represents you—your element, your polarity. Everything else in the chart is read in relation to it. If your Day Stem is 甲 (yang wood), then metal is what controls you, water is what nourishes you, fire is what you produce, and earth is what you conquer. The Ten Gods system names these relationships.
What Makes It Different from the I-Ching
The I-Ching is situational. You ask a question, cast a hexagram, and the answer applies to that question at that moment. You can ask again tomorrow and get a different hexagram. The oracle responds to the moment of inquiry.
Bazi is natal. The chart is fixed at birth. It does not change. What changes is the Grand Cycle (大運)—a sequence of ten-year periods derived from the month pillar, each governed by a different stem-branch pair. The natal chart is the terrain; the Grand Cycle is the weather moving across it.
The I-Ching asks: What is happening? Bazi asks: What kind of person is this, and what is the current season of their life?
The Three Canonical Texts
Bazi has hundreds of texts. Three define the tradition. They are not interchangeable—each does something the others do not.
淵海子平 — Yuanhai Ziping
The primer. Attributed to Xu Dasheng (徐大升) of the Song dynasty, it is the oldest surviving systematic Bazi text. It opens by laying out the Ten Gods as a complete relational framework—every stem defined against every other stem:
五乾屬陽，喜合。以甲為例
見甲：為比肩、兄弟。見乙：為劫財、敗財，克父及妻。見丙：為食神、天廚、壽星，為男。見丁：為傷官、退財、耗氣，子甥。
— 《淵海子平》基礎
Yang stems “like combination” (喜合). Yin stems “like clash” (喜沖). The same encounter—say, seeing 庚 (yang metal)—means “Seven Kills” for a 甲 day master but “Direct Officer” for a 乙 day master. Polarity flips everything. The Yuanhai gives you the complete lookup table, then spends twelve chapters applying it: spirit stars, six relatives, female destiny, rhymed formulas, and eighteen named structural patterns (格局).
三命通會 — Sanming Tonghui
The encyclopedia. Written by Wan Minying (萬民英) during the Ming dynasty, it runs twelve juan and 383 sections. Where the Yuanhai is a primer, the Sanming Tonghui is a reference work. It begins with cosmology—grounding the entire system in the movement from Taiji to yin-yang to the Five Phases:
天高寥廓，六氣迴旋以成四時；地厚幽深，五行化生以成萬物。可謂無窮而莫測者也。
— 《三命通會》卷一，論五行生成
It then catalogs everything: the sixty Jiazi cycle with Nayin pairings, all ten Heavenly Stems analyzed by seasonal context, seventy-three named structural patterns (compared to the Yuanhai's eighteen), complete day-by-hour reference tables for all 120 combinations, and extensive classical commentaries. If you need to look something up, this is where you look.
滴天髓闡微 — Ditiansu Chanwei
The polemic. The original verses are attributed to Jing Tu (京圖) of the Song or Yuan dynasty—terse, aphoristic, deliberately cryptic. The commentary that makes them usable was written by Ren Tieqiao (任鐵樵) during the Qing, and it is sharp-edged. Where the Yuanhai catalogs and the Sanming compiles, the Ditiansu argues. It has a thesis: most of what passes for Bazi is noise.
余詳考古書，子平之法，全在四柱五行。察其衰旺，究其順悖，審其進退，論其喜忌，是謂理會。至於奇格異局，神煞納音諸名目，乃好事妄造，非關命理休咎。
— 任鐵樵，《滴天髓闡微》知命
“The Ziping method lies entirely in the Four Pillars and the Five Phases. Examine their strength and weakness, investigate their harmony and opposition, assess their advance and retreat, determine what they favor and what they fear—that is understanding. As for exotic formats, spirit stars, Nayin, and other such labels—these are fabrications by the enthusiastic, unrelated to the actual workings of fate.”
Ren Tieqiao backs every claim with worked examples—real birth charts, including one attributed to Emperor Qianlong, analyzed stem by stem. The Ditiansu is the text that separates the structural logic from the accumulated folklore.
The Logic of Balance
All three texts agree on the central principle, even when they disagree on everything else. The Yuanhai states it as a set of interlocking rules:
金旺得火，方成器皿；火旺得水，方成相濟；水旺得土，方成池沼；土旺得木，方能疏通；木旺得金，方成棟樑。
強金得水，方挫其鋒；強水得木，方泄其勢；強木得火，方化其頑；強火得土，方止其焰；強土得金，方制其害。
— 《淵海子平》論五行生剋制化
Strong metal needs fire to become a vessel. Strong water needs wood to drain its force. Strong wood needs fire to transform its stubbornness. Every element, when excessive, needs a specific counterforce—not its destroyer, but its child. The generation cycle bleeds off excess; the control cycle shapes raw material into something useful.
This is the engine of Bazi reading. A chart is not “good” or “bad”—it is balanced or imbalanced, and the Grand Cycle either corrects the imbalance or deepens it. The Ditiansu puts it plainly:
戴天覆地人為貴，順則吉兮凶則悖。
— 《滴天髓》人道
“Between heaven and earth, the human is precious. Harmony brings fortune; discord brings calamity.” The system does not predict events. It maps the conditions under which a particular configuration of elements will thrive or struggle, and names the specific remedies—the elements that, when they arrive via the Grand Cycle or annual pillars, restore balance.
What This Series Covers
This series walks through the Bazi system using the three canonical texts as primary sources. Not modern interpretations, not simplified how-to guides—the actual classical Chinese, translated and explained.
- Part 2: The Sixty Jiazi and the Nayin—the sixty stem-branch pairs, their elemental signatures, and why the Sanming Tonghui starts here
- Part 3: The Ten Gods—the relational framework that turns eight characters into a readable chart
- Part 4: Reading Seasonal Strength—how the month pillar determines whether your Day Master is thriving or dying
- Part 5: Ge Ju — The Named Configurations—the structural patterns that classical texts treat as fate archetypes
- Part 6: The Xu Ziping Revolution—the historical pivot from year-based to day-based reading, and the Siku scholars' verdict
If you already work with stems and branches through the I-Ching, you have the vocabulary. Bazi gives that vocabulary a different job.