Decade Luck & Strength · 大運與日主強弱

The decades run from the Month pillar, ten years each. Direction: men born in a yang year and women born in a yin year go forward, the other two backward — the same convention as Zi Wei and the Palm Sutra. The starting age counts the days from birth to the next major term going forward, or from the previous one going backward, at three days to the year. Those terms are exactly the lines at which the month branch changes, and this tool uses that same boundary for both — so the decades and the Month pillar can never disagree.

Day-Master strength

How strength is scored (schools weight this differently, so the method is stated): the eight characters — four stems and the hidden stems of four branches — are split into support (same element as the Day Master, plus what generates it) and drain (what controls it, what it generates, what it controls). The month branch commands the season and counts double; a branch’s main hidden stem counts 1 and the others 0.5. The difference over the total gives a ratio from −1 to +1, banded at ±0.15. This is a transparent measure, not a verdict — choosing a useful god also involves climate (hot/cold, dry/damp), bridging elements and whether the structure holds, none of which a weight table settles. This tool gives the indicator and stops there.

The three bands

• strong — The Day Master runs strong: more support than drain. Stamina and conviction are there and pressure is bearable; such charts usually want an outlet rather than more reinforcement.
• balanced — The Day Master is balanced: support and drain are close. A flexible structure with room to manoeuvre; what it needs shifts with the decades and years rather than being fixed.
• weak — The Day Master runs weak: more drain than support. Energy depletes and sustained pressure tells; such charts usually want reinforcement — mentors, learning, allies — over brute effort.

Hidden stems 藏干

A branch is not a single element. Each hides one to three stems — a main one plus secondary ones — and the Ten Gods really come from these hidden stems. Reading only the four visible stems leaves just three to work with (the Day stem is the self); the hidden stems let every branch say whether it is wealth, authority or resource to the Day Master.

Choosing a useful god (用神) is deliberately not offered here. It depends on climate, bridging elements and whether the structure holds — judgement a weight table cannot stand in for. The tool gives a transparent indicator and stops.

Cast a chart and step through the decades at https://localpapa.com/tools/bazi.html.

Annual fortune · The Ten Gods · Day masters · BaZi knowledge base

機器可讀原始檔（供 AI 檢索）：/okf/bazi/luck.md