Hai-Wei Hidden Arch toward Mao Wood

Hai, Mao, and Wei form the Wood Three Combination. Hai is Wood's growth stage, Mao its peak, and Wei its storage stage. When Hai and Wei are present while Mao is absent, modern BaZi commonly describes the two outer branches as arching toward the missing center, Mao.

Classical texts record both Three Combination structures and the broader method of arching, although they do not always use today's standardized label “Hai-Wei Hidden Arch toward Mao.” The modern term is based on the underlying Hai-Mao-Wei growth, peak, and storage structure.

Hai-Mao links Wood's growth and peak stages, while Mao-Wei links peak and storage. Both contain Mao directly and are treated as Half Combinations. Hai-Wei lacks Mao, so it is an arch rather than the same type of Half Combination.

The key difference is whether Mao actually exists in the chart. A Half Combination includes the central branch; the Hidden Arch contains only the two outer members of the full Wood structure.

The relationship is not derived from a simple claim that Water and Earth directly generate Wood. It comes from Wood's twelve-stage cycle: Hai is the growth position, Mao is the peak, and Wei is the storage position.

Hai therefore remains a Water branch and Wei remains an Earth branch. The Wood arch describes their latent connection within the Hai-Mao-Wei structure rather than a change in their basic Elements.

If Mao appears in the natal chart or through a luck period, Hai, Mao, and Wei now have the form of the complete Wood Three Combination. The structure should then be reassessed as a full combination rather than only as a Hidden Arch.

A Hidden Arch is not the same as a complete Wood structure and is not automatically favorable. Once Mao is present, the actual strength of Wood still depends on season, overall balance, and other Branch interactions.