BAZI KNOWLEDGE BASE
Principal, secondary and residual qi: how hidden-stem layers differ
Principal qi is an Earthly Branch’s main elemental component; additional hidden stems describe other qi it contains. Middle and residual qi are labels used to distinguish those components, but a list’s second and third positions do not establish a universal classification. Chen is often displayed as Wu, Yi and Gui, yet its second entry, Yi Wood, is described traditionally as the remnant of spring Wood. These distinctions help identify the support a stem receives rather than assign fixed proportions to a person.
Principal qi identifies the branch’s main element
Yin’s principal stem is Jia Wood and Mao’s is Yi Wood, so both are Wood branches. Chen is classified as Earth through principal Wu despite also containing Yi Wood and Gui Water. Zi’s principal Gui and Wu branch’s principal Ding remain Yin stems even though those branches are Yang.
A branch need not fill three slots. Zi, Mao and You each contain one hidden stem, while Wu and Hai contain two. Principal, middle and residual are not three compulsory boxes for every branch.
Middle qi is not reliably identified by second position
In a common layered description, Bing Fire in Yin is called middle qi, distinguished from principal Jia Wood and accompanying Wu Earth. For Chen, Xu, Chou and Wei, clarify whether the account is classifying hidden components, seasonal remnants or storehouse associations. Different display orders do not necessarily disagree on contents.
Chen makes the problem clear: a table can list Wu, Yi and Gui while a classical passage calls Yi residual qi. The first lists members; the second describes spring Wood continuing into Chen month. Identify the actual hidden stem before interpreting the label.
Seasonal remnants and stored qi in the four Earth branches
Here, residual qi means the continuation of the preceding seasonal influence, while stored qi follows elemental storage correspondences. The table combines those seasonal positions with the standard hidden stems; it does not claim every school calls one column middle qi.
Ziping Zhenquan uses Yi meeting Chen and Ding meeting Wei as residual-root examples. Its mixed-qi discussion distinguishes Chen’s Earth, remaining Wood and Water storage. Residual does not mean functionless or describe a person’s leftover talent.
| Branch / season | Principal Earth | Seasonal remnant | Stored hidden stem |
|---|---|---|---|
| Chen / late spring | Wu | Yi Wood | Gui Water |
| Wei / late summer | Ji | Ding Fire | Yi Wood |
| Xu / late autumn | Wu | Xin Metal | Ding Fire |
| Chou / late winter | Ji | Gui Water | Xin Metal |
How principal and additional roots differ in practice
Jia Yin gives Jia an exact principal Wood root. Bing Yin gives Bing a Fire root inside a branch whose principal element is Wood. Ding Wei gives Ding a residual Fire root. All three pillars contain exact-character support, but that does not make the support identical.
Yi can also find residual Yi Wood in Chen elsewhere in a chart. This does not invent a Yi Chen pillar, which is absent from the sexagenary cycle (the repeating sequence of sixty paired calendar symbols). A cross-pillar root requires the stem and branch positions to be named separately.
Root quality also involves the birth season and other support. Xin finds Xin Metal in both You and Xu, but You is principally Metal while Xu is principally Earth with additional Xin. The distinction matters without settling the strength of an entire chart from one root.
Why hidden-stem and monthly timing tables can differ
A hidden-stem table lists a branch’s assigned contents. A monthly command table divides a solar-term (one of 24 seasonal markers defined by the Sun’s position along its yearly path) month into intervals and describes which qi operates then. Sanming Tonghui assigns seven days to Ren and twenty-three to Gui in Zi month, while the standard hidden-stem table lists only Gui in Zi.
This does not permanently add Ren to Zi’s hidden stems. The two tables answer different questions. Historical interval lengths and characters also vary; an account using that method should identify its source, solar-term boundary and chosen rule instead of substituting hidden-stem list positions.
Are hidden-stem weights always 60%, 30% and 10%?
No fixed percentage set replaces strength analysis for every chart. Display order, a software weighting convention and monthly interval lengths are three different ideas. Combining them into one percentage turns an estimate into an apparent fact.
Exposure may also change a component’s importance in pattern reading. Ziping Zhenquan discusses Bing appearing in Yin month, showing why the analysis need not stop at principal Jia. A reader benefits more from knowing why a root matters under the given season, exposure and contacts than from an unexplained score.