Ṣaḍbala · the six strengths

Ṣaḍbala means “six strengths.” It is the classical scheme, set out most fully in the Bṛhat Parāśara Horā Śāstra, for totaling a planet’s strength from six separate sources and reading them as one number. The six are sthāna bala, positional strength from dignity across the signs and vargas; dig bala, directional strength from the house-angle each planet favors; kāla bala, temporal strength from time of day, fortnight, and year; cheṣṭā bala, motional strength tied to retrogradation; naisargika bala, the fixed natural order running from the Sun, strongest, down to Saturn; and dṛg bala, aspectual strength, the net of benefic and malefic glances a planet receives.

Each strength is computed in a unit called rūpa and the six are summed, then measured against a threshold said to be needed before a planet is counted strong. The exact figures vary a little by source, so the codex reports the method and its parts rather than one authoritative table.

A planet can promise much and still lack the strength to pay it.

The point of the sum is practical. Ṣaḍbala is a way to weigh which grahas actually deliver. A planet strong across the six is read as able to give its results in full, while a planet weak in the total is held to promise more than it can produce, whatever its sign and house otherwise suggest.