Every degree of the zodiac is governed by a hierarchy of three lords:
Sign Lord (weakest): The classical ruler of the sign. Sun rules Leo; Mercury rules Virgo. The sign lord provides general flavor but not the determining factor.
Star Lord / Nakshatra Lord (middle): The 27 nakshatras are ruled by planets in Vimshottari order (Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury). If a planet is in Ashwini nakshatra (1st), Ketu is the star lord. Star lord influences the outcome more than sign lord.
Sub-Lord (strongest / FINAL AUTHORITY): Each nakshatra is divided into 9 unequal sub-periods using Vimshottari dasha year ratios (7, 20, 6, 10, 7, 18, 16, 19, 17 = 120 years). The 9 sub-lords are Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury, in sequence. The sub-lord is the final determinant of outcome.
Example: Planet at 15°44' in Virgo: Virgo is ruled by Mercury (sign lord). The degree falls in Hasta nakshatra (star lord Moon). Hasta is divided into 9 parts; 15°44' falls in the 6th part, ruled by Rahu (sub-lord). In KP reading, Rahu is the effective ruler, not Mercury or Moon.
Key principle: If sub-lord is benefic for the question (e.g., for a 7th house query, if sub-lord is Venus or Jupiter), outcome is YES. If sub-lord is malefic (Saturn, Mars, Rahu), outcome is NO or DELAYED. Sign lord and star lord provide context but do not override sub-lord verdict.
The calculator resolves sign-star-sub hierarchy for any degree. You will practice identifying sub-lords for key planets and house cusps and apply the hierarchy to predict outcomes.