Hidden Stems
The one to three Heavenly Stems contained within each Earthly Branch. The strength of an Earthly Branch is only clear when its Hidden Stems are considered.
The one to three Heavenly Stems contained within each Earthly Branch, also called 'Human Element'.
For example, the Yin (寅) branch contains Jia (甲), Bing (丙), and Wu (戊) — Jia is the Primary Qi (strongest), while Bing and Wu are Residual Qi. The Cardinal branches (Zi, Wu, Mao, You) contain the fewest Hidden Stems, while the Storage branches (Chen, Xu, Chou, Wei) contain the most.
⚠️ The Five Element statistics on this site use a scope of four Heavenly Stems plus all Earthly Branch Hidden Stems, for a total of thirteen. The Primary Qi of an Earthly Branch is already included in its Hidden Stems and is not counted separately. Different tools use different scopes; this is usually why the numbers don't match, not because someone calculated incorrectly.