Seven Regulators & Four Shadows vs. Vedic Astrology: Similarities and Differences

Seven Regulators & Four Shadows and Vedic astrology are both ancient, long-lineaged systems of stellar fate. They share a good deal, yet each has its own temperament. Here is a point-by-point comparison.

1. Seven Regulators & Four Shadows needs a birth time only to the double-hour (two hours). It does not depend on precision down to the minute or second; instead it defines the chart through many structural parameters — the Heavenly Stems and Earthly Branches of the year, month, day, and hour, the stellar transformations, the lunar mansions, and more. Vedic astrology, by contrast, defines the chart from a precise birth time. One reads structure, the other reads time; the two place their precision in different places.
2. Its Earthly Branches are the Vedic signs. Zǐ, chǒu, yín, mǎo, chén, sì, wǔ, wèi, shēn, yǒu, xū, hài correspond to Mesh, Vrishabh, Mithun, Kark, Simh, Kanya, Tula, Vrischik, Dhanu, Makar, Kumbh, and Meen.
3. It uses conceptual points. The Four Shadows are exactly that — virtual locations in the sky rather than physical bodies. In Vedic astrology these are called the UpaGrahas (shadow planets) and the subtle points KaalVela and Pranapad.
4. The charts look different. A Seven Regulators & Four Shadows chart is usually round; square ones exist but are less common. Vedic astrology is most recognizable by the North Indian chart, which is diamond-shaped and usually places the first house at the top center; the South Indian chart is also distinctive — square, but with the signs running clockwise, unlike the counter-clockwise flow of Seven Regulators & Four Shadows.
5. Seven Regulators & Four Shadows uses eleven bodies; Vedic uses nine. Seven Regulators & Four Shadows uses the Sun, Moon, Venus, Mercury, Jupiter, Mars, Saturn, plus Ethereal Benevolence, Lunar Apogee, Ketu, and Rahu. Vedic astrology uses the Sun, Moon, Venus, Mercury, Jupiter, Mars, Saturn, Ketu, and Rahu.
6. Rahu and Ketu are reversed between the two systems. Rahu and Ketu are the Moon's south and north nodes. In Seven Regulators & Four Shadows, Rahu is the south node and carries the shadow force of Mars, while Ketu is the north node and carries the shadow force of Saturn. In Vedic astrology, Rahu is the north node and Ketu is the south node. The interpretations are broadly alike — only the names are swapped — and Vedic does not give Rahu and Ketu the Fire and Earth natures that Seven Regulators & Four Shadows does.
7. Neither needs an aspect orb to take effect. In Seven Regulators & Four Shadows, every star influences the house opposite it and its trine houses. Vedic is more particular: different bodies have different aspect patterns. The Sun, Moon, Venus, Mercury, Jupiter, Mars, Saturn, Ketu, and Rahu all influence the house opposite them; Mars additionally influences the 4th and 8th houses from its position; Saturn additionally the 3rd and 10th; and Jupiter, Ketu, and Rahu additionally the opposite house plus the 5th and 9th.
8. Both have a star whose light is overwhelmed when it sits too close to the Sun. Seven Regulators & Four Shadows calls this state "submerged"; Vedic astrology calls it combustion, or being burnt.