Astrology describes how a person draws close, what they like, how they ask and how they refuse. It is a reading of affective repertoire, and not of romantic destiny, what it delivers is vocabulary for conversations that usually happen with none.

And it does not start with the Sun sign. That sounds odd because the whole conversation about astrology and love, outside a consulting room, turns on twelve words. Inside a chart, the Sun is the piece that says least about the subject: it says what somebody's life is organised to develop, and loving is nobody's organisation.

Venus says what you like; Mars says how you go after it. They are the two pieces that answer for attraction, and both are almost never in the sign a person gives when somebody asks.

We measured 124,185 charts, every six hours between 1940 and 2025. Venus is in the same sign as the Sun in 23.7% of them, which means three out of every four people of your sign like things from another one. A text describing the love life of Aries by talking only about the Sun misses the target in three quarters of cases.

There is an astronomical detail that makes this even more concrete. Venus never moves more than 47.3 degrees away from the Sun, that is its maximum elongation, measured for the interval from 1900 to 2100. Since each sign spans thirty degrees, your Venus can only be in five of the twelve signs: the one holding your Sun, the two before or the two after. Five possibilities, and knowing which of them is yours requires the date, not the sign.

Mars has no such tether and can be in any sign. It is the piece of desire and initiative: how a person advances, how they fight, what makes them give up. A delicate Venus with an impatient Mars describes somebody who wants slowly and moves fast, and that contradiction is more informative than any Sun sign adjective.

And there is a third piece that almost never enters the conversation about love, and it decides a good part of what happens after the infatuation. The Moon says what a person needs in order to feel safe, and that is what surfaces once the novelty wears off and the two begin living inside each other's routine. It changes sign every two and a half days, so it does not always match between people born in the same week.

Venus, Mars and Moon answer, in that order, what attracts, how one goes after it and what makes one stay. All three appear in the chart before any consideration about the Sun sign, and all three require the full date.

A concrete case of how the three pull apart: somebody with Venus in Pisces, Mars in Capricorn and Moon in Gemini likes in a romantic way, advances in a calculated way and needs conversation in order to feel at home. The three pieces of information contradict each other on the surface, and it is precisely the contradiction that describes a real person instead of an archetype.

Love, in a chart, is not one single subject, there are three, and they do not translate into one another.

• The fifth house is flirting, pleasure, play and whatever is done for the taste of it. It is where the attraction that asked nobody for a commitment lives.
• The seventh house is the formalised bond: marriage, partnership, the agreement of two. It describes the kind of partnership a person looks for, and not the person who will turn up.
• The eighth house is the intimacy that mixes resources, body and mutual dependence. It is where a couple finds out what each of them does when they need the other.

Much frustration with love readings comes from confusing the three. Somebody with a busy fifth house and an empty seventh has an intense affective life and little interest in a contract, and neither of those is a problem, until somebody calls the second one failure. All three houses depend on the hour of birth, because the houses go all the way around once a day.

The arithmetic takes the idea apart on its own. There are 78 possible pairs of Sun signs, counting each duo once. There are billions of couples in the world. A table of 78 lines would have to explain all of them.

And within a single pair the variation is enormous. Two people of Aries with Libra can each have Venus in five signs, Moon in twelve and Ascendant in twelve. Multiply it out: the same pair of Sun signs holds more than five hundred thousand different combinations of those three pieces. Saying that Aries and Libra go well together is saying one thing about five hundred thousand situations at once.

The compatibility table has a practical origin, and it is the same as the newspaper horoscope's: the newspaper format had only the date of birth to work with. Under that constraint, crossing twelve by twelve was the most that could be done. The constraint disappeared when calculation became instant; the table stayed.

Synastry is the comparison of two whole charts. It looks at two things: which house of one the planets of the other land in, and what angles the planets of the two form between them. The result is a portrait of fit and friction, made of specific points.

What it shows well: where the two understand each other with no effort, where one always has to translate what they meant, and which subject tends to come back in the same argument for years. That is usable, knowing that a couple's friction is about pace and not about affection changes the conversation they manage to have.

What it does not do: say whether the relationship will last, point out the right person, or give a couple a score. No synastry configuration is an impediment, and none is a guarantee. Couples with heavy friction on paper last decades by decision of both, and couples perfect on paper end within a year.

Astrology names what was already going on, and a name is the beginning of any conversation. Three concrete things, and none of them is a forecast:

• It translates a difference into neutral language. A person who needs time alone and another who needs presence become, in the reading, two legitimate needs, instead of indifference on one side and nagging on the other.
• It shows what each one asks for without knowing how to ask. That is the Moon's job in a reading: what the person needs in order to feel safe, which is almost always different from what they put into words.
• It anticipates the subject that comes back. A structural friction between two charts does not vanish with goodwill; knowing which one it is lets a couple agree on how to handle it instead of treating each appearance as news.

In the catalogue this comes in three different readings, and what tells them apart is the material each one asks for: Love Chart reads your chart alone and describes your affective repertoire; Love Synastry: Couple Compatibility compares two charts; Where to find love works with place and circumstance. All of them begin with the drawing of the sky, which comes first and free of charge.

Astrology does not say who the person is nor when they arrive. A chart describes the kind of bond somebody looks for and what tends to happen inside it. Name, face and date are not there, and any reading offering them has stepped out of its place.

It decides for nobody. No configuration authorises ending a marriage, and none forces anybody to stay. The reading delivers information; the choice stays with whoever lives the relationship.

And it is no diagnosis. Suffering in a relationship has causes astrology does not reach, and a serious reading takes no therapist's place. Where astrology has no answer, saying so is part of the work.

And the questions that come up most on this subject, with the short answer: