Two readings, combined
The match rate comes from two separate readings. Saju compatibility reads the full four-pillar chart of both people. Zodiac compatibility reads a single character — the branch of the birth year, which is what an animal sign actually is. The two are combined as a weighted average.
| Reading | What it looks at | Weight |
|---|---|---|
| Saju | Four factors drawn from the whole chart | 70% |
| Zodiac | One relation between two year branches | 30% |
Saju weighs more because it uses far more information. We keep the zodiac anyway for two reasons: it is the part everyone already understands, and it is the only axis that does not move when the birth time is unknown.
The four Saju factors
Year
Stem
Branch
roots · zodiac animal
Month
Stem
Branch
season · strength
Day
Stemday stem = you
Branchday branch = partner seat
you · your partner seat
Hour
Stem
Branch
later years · how it is used
| Factor | What it asks | Weight |
|---|---|---|
| Day master relation | What each person's day stem is to the other, read as one of the Ten Gods | 32% |
| Elemental supply | Does the other person carry the element you currently lack | 25% |
| Spouse star | Does the other person's day stem sit in your spouse position | 23% |
| Day branch relation | Whether the two day branches attract or clash | 20% |
The day branch matters because in this tradition it is the spouse position — of the four pillars, that is the one that speaks about a partner.
The branch relation table
Both the day branch and the year branch are judged with the same table. These are the actual numbers the service uses.
| Relation | Meaning | Score |
|---|---|---|
| Samhap | Three branches forming a complete bureau | 95 |
| Yukhap | A pair that draws together | 90 |
| Banhap | Half of a bureau, including its leading branch | 88 |
| Same branch | Alike, but not drawn together | 72 |
| Neutral | No named relation | 68 |
| Wonjin | Quiet, lasting friction | 52 |
| Chung | A head-on clash | 45 |
Note that the floor is 45, not zero. In this tradition a clash is a collision, not an ending. Scoring it near zero would let the service pronounce a verdict on a relationship, which is not what it is for.
Rules only — no AI, no randomness
Every number above is a rule. Nothing is generated by a language model and nothing is random, so the same two birth dates always produce the same result. Since we store nothing, that determinism is what stands in for a saved record.
When we change a scoring rule we raise the engine version, which is printed under your result. That tells you which set of rules produced the number you are looking at.
Birth time and birth place
The birth time is optional. Without it we leave out the hour pillar and mark the result accordingly. If you do know it, please also pick the city — clock time and solar time differ by up to half an hour, and the hour pillar changes in two-hour steps, so people born near a boundary land in the wrong pillar without the correction.
What this is not
This is a reading offered from the perspective of a traditional East Asian system. It is not a scientific prediction, and it is not a verdict on any relationship. Read it as one angle on two people, not as an answer.
For what happens to the dates you type, see what we store.