Bazi Basics: What Is Bazi? Four Pillars, the Heavenly Stems & Earthly Branches, and Yin-Yang of the Five Elements

TL;DR (Read in 30 Seconds)

1. What Exactly Is Bazi? One Sentence

Many people first encounter Bazi through “fortune telling,” so it can feel mysterious. But if you look at it as an information system, it’s surprisingly structured:

Each of the four parts (year/month/day/hour) is written with two characters (one stem + one branch). Four pairs make eight characters — hence the name “Bazi.”

2. What Are the Four Pillars? Why Bazi Is Also Called Four Pillars

When you lay out Bazi by year, month, day, and hour, you get four “columns”:

• Year Pillar
• Month Pillar
• Day Pillar
• Hour Pillar

That’s why Bazi is often called the Four Pillars. You can think of “Bazi” as the content and “Four Pillars” as the structure.

3. Gregorian Calendar, Lunar Calendar, and the Ganzhi Calendar: Why Bazi Uses Ganzhi

In daily life, people usually describe birthdays using two systems:

1) Gregorian calendar

The most common date system in modern life.

2) Lunar calendar

Often used in traditional contexts and festivals.

3) Ganzhi calendar (used by Bazi)

Bazi does not write dates as numbers directly. Instead, it converts them into stem-branch pairs:

• Year: Heavenly Stem + Earthly Branch
• Month: Heavenly Stem + Earthly Branch
• Day: Heavenly Stem + Earthly Branch
• Hour: Heavenly Stem + Earthly Branch

This conversion step is what people call casting a Bazi chart: once the birth time becomes Four Pillars in Ganzhi, you finally have a “chart” that can be read and analyzed.

4. How to Learn Bazi From Scratch: Master These 3 Basics First

If you want to learn Bazi as a beginner, I suggest this order:

1. Five-Element & Yin-Yang attributes of stems and branches (the focus of this article)
2. Generating/controlling relationships of the Five Elements (how Wood/Fire/Earth/Metal/Water interact)
3. The Ten Gods (the naming system for relationships like Direct Wealth, Indirect Wealth, etc.)

Most people get stuck not because it’s impossible, but because they rush past step 1.

5. The Ten Heavenly Stems: Which Five Element Do They Belong To?

There are 10 Heavenly Stems:

Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, Gui

They correspond to the Five Elements, and each element has Yin/Yang. A practical way to remember Yin/Yang differences is by imagery:

Wood: Jia (Yang Wood) vs Yi (Yin Wood)

• Jia: like a tall tree — outward, upright
• Yi: like vines/flowers — flexible, delicate

Fire: Bing (Yang Fire) vs Ding (Yin Fire)

• Bing: like the sun — bright, expressive
• Ding: like candlelight — warm, subtle

Earth: Wu (Yang Earth) vs Ji (Yin Earth)

• Wu: like a mountain/wall — solid, supportive
• Ji: like farmland — nourishing, adaptable

Metal: Geng (Yang Metal) vs Xin (Yin Metal)

• Geng: like blades/weapons — firm, decisive
• Xin: like jewelry/needles — refined, precise

Water: Ren (Yang Water) vs Gui (Yin Water)

• Ren: like rivers/seas — powerful, flowing forward
• Gui: like rain/springs — gentle, permeating

If you’re doing beginner practice like “Bazi charting” or “Five-Element lookup,” start by simply classifying each character into its element. The Yin/Yang imagery will deepen with use.

6. The Twelve Earthly Branches: How Do They Map to the Five Elements?

There are 12 Earthly Branches:

Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai

Branches also have Five-Element (and Yin/Yang) attributes. As a beginner, a quick intuition is to link them to seasonal qi:

1) Yin/Mao are Wood: spring growth

Spring is about renewal and expansion — Wood qi is strong.

2) Si/Wu are Fire: summer heat

Summer rises upward with warmth — Fire qi is strong.

3) Shen/You are Metal: autumn contraction

Autumn is about harvesting and restraint — Metal qi is strong.

4) Hai/Zi are Water: winter storage

Winter is cold and inward — Water qi is strong.

5) Chen/Xu/Chou/Wei are Earth: the “connectors” between seasons

These four branches are commonly treated as Earth, often placed at seasonal transitions, carrying a bridging and stabilizing role.

7. Practice: Treat “Recognizing Characters” as the First Gate

Here is the most effective exercise you can do right now:

1. Cast a Bazi chart to get the Four Pillars
2. Mark the Five Element for each stem and branch
3. Only do recognition first — don’t rush into strength/weakness or “useful elements” yet

Once you can quickly see the overall distribution of Wood/Fire/Earth/Metal/Water in a chart, the next steps (element interactions and Ten Gods) become much easier.

8. Common Beginner Mistakes (4 Traps)

1. Memorizing terms without classification: being able to map stems/branches to elements matters more than memorizing definitions.
2. Analyzing without a chart: Bazi is based on the Ganzhi calendar — without a chart there is no structure.
3. Chasing conclusions too early: practice recognition first, then move to strength, patterns, and useful elements.
4. Treating fortune telling as deterministic prediction: it’s better viewed as a traditional framework for self-observation and decision support.

9. FAQ

1) What is the difference between Bazi and Four Pillars?

There is no real difference. “Bazi” emphasizes the eight characters; “Four Pillars” emphasizes the year/month/day/hour structure.

2) Why must we cast a chart?

Because Bazi analysis depends on your birth time expressed in stem-branch pairs. Casting a chart converts a Gregorian/lunar birthday into the Ganzhi calendar so the Four Pillars can be read.

3) What if I can’t memorize stems and branches?

Start with Five-Element classification:

• Jia/Yi = Wood, Bing/Ding = Fire, Wu/Ji = Earth, Geng/Xin = Metal, Ren/Gui = Water
  Then use imagery to remember Yin/Yang differences, and practice 5 minutes a day with your own chart.

4) What is the relationship between “Five-Element lookup” and Bazi?

Every stem and branch in Bazi has a Five-Element attribute. A “Five-Element lookup” is essentially the first step: mapping chart information into Wood/Fire/Earth/Metal/Water.