Guide
BaZi compatibility
What a full BaZi compatibility reading actually compares (eight characters each) and why the year animals are the least of it.
BaZi compatibility compares two complete four-pillar charts (eight characters each) to read how two people's stems, branches, Day Masters, and ten-year chapters interact. It goes far beyond year-animal matching, which uses only two of the sixteen characters involved.
Two charts, not two animals
Most of what the internet calls BaZi compatibility is really year-animal matching: Rat loves Dragon, Horse clashes with Rat, done. It's fast, it's memorable, and it leaves out six of the eight characters in each chart.
A full reading compares two complete charts: eight characters each. How the stems meet across the pair. How the branches meet. What the two Day Masters do to each other. And which ten-year chapters both people are living through right now. The year animals are still in the room. They're just not running the meeting.
How the stems meet
Stems are the visible layer: what each person shows the world. When two charts meet, certain stems fuse. 丁 and 壬, for instance, combine toward wood: two people's outward styles merging into something neither has alone. It reads like a shared gear: the pair can do something together that neither does separately.
Other stems oppose: 甲 meets 庚, 丙 meets 壬. A stem clash is not a verdict. It's usually where the pair is most different in how they operate: the exact spot that becomes either the division of labor or the recurring argument, depending on the rest of the charts.
How the branches meet
Branches are the ground floor: instincts, private habits, what happens at home. They relate in a small set of old patterns: the harmonies that bind, the clashes and harms and punishments that rub.
A harmony between branches (say, one person's Snake year meeting the other's Rooster month) gives the pair a shared channel: something that works without discussion. A clash gives them movement: the place where the relationship keeps changing shape.
Neither is good or bad on its own. A chart with no friction in it at all is usually a chart where nothing moves. Practitioners worry less about clashes than about pairs with none: friction is what keeps a relationship from going stale.
The two Day Masters
Then the two people themselves. In five-element terms, one person's chart may feed the other's: fire feeds earth, earth bears metal. What one of you does easily is what steadies the other.
Or one may shape or drain the other. None of this is a ranking. A pairing where both charts feed each other can feel effortless and go soft; a pairing with more friction can stay sharp for decades. What matters is knowing what the dynamic is, so you can use it on purpose.
The chapters they're in
Finally, timing. Each person is living through a ten-year chapter, and the two chapters meet too. Two people in demanding chapters will feel each other differently than the same two people in easy ones. A rough year in a relationship is sometimes just two hard chapters overlapping. It passes with the chapter, not with the person.
This is the layer year-animal matching can't see at all, and it's often the one that explains the most.
What it can't say
A compatibility reading can't tell you what the other person feels. That's theirs to tell you. It can't tell you whether to stay or go. What it can do is give you a second, impersonal account of the patterns between you, so the argument stops being about who's wrong and starts being about what the pattern needs.
Aster never speaks for the other person. The reading describes what runs between you, and leaves the rest to the two of you.
What to look for in the two charts
Start with the two Day Masters: does one feed the other? Then look for a harmony or a clash between any two branches: that's usually where the relationship has its weather. Then check the chapters: both demanding, both easy, or one of each?
Three observations, and you're already reading the pair more accurately than any year-animal chart can.