How rare is a placement

There is no register of everyone's birth moment, so Genastro builds a sample. It draws 2,000,000 simulated births dated 1950 to 2024 and gives each a place and a time of day. Every chart is computed by the same engine that computes yours. A frequency is the share of those charts with a placement.

Places are chosen with population weighting, so a birth in a large city is likelier than one in a small town. That matters because the Ascendant depends on where you were born.

Births are not spread evenly over the year or the day, so the simulation uses a seasonal curve and an hour-of-day curve. Both are plain mathematical shapes chosen by hand to be plausible. They are not fitted to real birth statistics, and any figure that depends on them inherits that limit. A fit would need real counts by day and hour, and this sample does not use them.

The window also shapes the slow planets. Pluto's share in Scorpio is a share of births from 1950 to 2024. It reflects which years are in the sample, not how long Pluto stays in the sign.

A rank always names its direction. "2nd rarest of 12" and "2nd most common of 12" are opposite ends. In a group larger than twelve, close ranks fall within sampling noise, so they are printed as "about". A rarity is a count, not a verdict.

To check the arithmetic, divide. An even split of twelve signs is 8.33% each, of 144 Sun and Moon pairs 0.69% each, and of 1,728 big threes 0.058% each.