Heavenly Stems

The ten Heavenly Stems (Tian Gan) come in five pairs, one for each of the Five Elements: wood, fire, earth, metal and water. In each pair the first stem is yang and the second is yin, so Jia is yang wood and Yi is yin wood. Enter your birth date and time in the free BaZi calculator to get your four pillars; the top character of each pillar is one of your stems, and its color shows its element.

The images are a traditional way to remember what each stem is like.

Within the same element, a yang stem tends to be more outgoing and a yin stem more reserved. The yang stems are Jia, Bing, Wu, Geng and Ren. The yin stems are Yi, Ding, Ji, Xin and Gui.

In practice, polarity matters most for telling the direct and indirect Ten Gods apart. The Ten Gods are the ten ways another stem can relate to your Day Master. Take a stem that controls your Day Master: with the opposite polarity it is Direct Officer, and with the same polarity it is Seven Killings.

No. When two stems combine, they do not turn into another element; they only hold each other back. There are five combinations, each made of one yang and one yin stem, and in each pair one controls the other.

Many books say Jia and Ji combine and transform into earth. Our BaZi reports read only the holding back, not the transformation, so the wood stays wood and the earth stays earth.

A combination also fails when a stem that controls one of the pair sits between them. Say Jia is the year stem and Ji the day stem, with Geng in the month stem between them. Geng Metal controls Jia Wood, so the pair does not combine.

The four stem clashes are Jia–Geng, Yi–Xin, Bing–Ren and Ding–Gui. Both stems in a pair share the same polarity, and one controls the other: Geng Metal controls Jia Wood, for example.

Wu and Ji are earth, which tradition places in the center, so they have no opposite stem and no clash.

A clash means two forces pulling against each other. In BaZi, clashes and combinations both count as the weightier relationships.

The stems are the visible layer of a BaZi chart, and the Earthly Branches are the roots underneath. The stem of your day pillar is your Day Master, which stands for you. For the other three stems, check whether they have roots in the branches.

• RootedA branch hides a stem of the same element. A rooted stem carries more real weight, yin or yang alike.
• RevealedAn element hidden in a branch also shows up among the stems.

A force that is both revealed and rooted has the clearest effect.

The sixty-pair cycle (Liu Shi Jia Zi) is what you get by pairing stems and branches in order. There are ten stems and twelve branches, paired one by one starting from Jia Zi. Yang stems only meet yang branches and yin stems only meet yin branches, so one full round gives exactly sixty pairs.

Years, months, days and hours are all counted in these sixty pairs. The four pillars of a BaZi chart are four of them.