Shadbala: Six-Fold Planetary Strength (六力量體系)
Shadbala (ஷட்பலம்) is the comprehensive quantitative system for measuring planetary strength in Vedic astrology. The name means 'six strengths' (Shad = six, Bala = strength). It provides an objective numerical framework for comparing planetary power, essential for determining which planet dominates in competitive configurations and which Yogas will actually manifest.
The Six Components
- 1. Sthana Bala (Positional Strength): Derived from five sub-factors — Uchcha Bala (exaltation strength), Saptavargaja Bala (divisional chart strength), Ojhayugma Bala (odd/even sign placement), Kendra Bala (angular house strength), and Drekkana Bala (decanate strength). This measures how well the planet is placed by sign and house.
- 2. Dig Bala (Directional Strength): Each planet gains maximum strength in a specific direction/house. Jupiter and Mercury are strongest in the 1st house (East), Sun and Mars in the 10th (South), Saturn in the 7th (West), Moon and Venus in the 4th (North). Parallels the Chinese concept of seasonal prosperity (旺) for elements.
- 3. Kala Bala (Temporal Strength): Based on birth time — day/night birth, weekday lord, month lord, year lord, and Hora lord. Diurnal planets (Sun, Jupiter, Venus) gain strength during day; nocturnal planets (Moon, Mars, Saturn) during night.
- 4. Cheshta Bala (Motional Strength): Based on planetary speed and retrograde motion. Retrograde planets gain Cheshta Bala as they appear brighter and closer to Earth. For Sun and Moon, this is replaced by Ayana Bala (solstice-based strength).
- 5. Naisargika Bala (Natural Strength): The inherent strength of each planet, fixed and unchanging. In descending order: Sun (60), Moon (51.43), Venus (42.85), Jupiter (34.28), Mercury (25.71), Mars (17.14), Saturn (8.57). This is the tiebreaker when other Balas are equal.
- 6. Drik Bala (Aspectual Strength): Strength gained or lost through aspects from benefic or malefic planets. Benefic aspects add strength; malefic aspects reduce it.
Minimum Required Strengths (Rupas)
Each planet requires a minimum Shadbala score to be considered functionally strong: Sun 390, Moon 360, Mars 300, Mercury 420, Jupiter 390, Venus 330, Saturn 300 Virupas (1 Rupa = 60 Virupas). Planets falling below these thresholds are considered weak regardless of sign placement.