Mathematical Astrology Part I  

The Sixfold Source of Planetary Strength ( Shad Bala )

We have said that Vedic Astro Physics is the integration of 3 sciences -
Siddhanta ( Astronomy), Samhita ( Philosophy & Maths) & Hora ( Astrology ).Astronomy or Siddhanta is the base, the scientific aspect and Astrology or Hora is the predictive aspect of that infinite ocean which is the Science ofTime, Vedic Astro Physics !


60 Shashtiamsas constitute a Rupa, a unit of planetary strength. A planet 

in order to be powerful should get a minimum of Shashtiamsas. For example, Jupiter should have at least 390 Shashtiamsas to be considered powerful. If he attains a Shad Bala of less than 390, he is considered Vibala or weak. Remedial measures have to be done for such a weak planet.



Knowest thou not that planets called Vibala
Are planets weak in the Sixfold Strength?
Cancellation ( Bhanga ) they cause of Regal Yoga
And are harmful in their nature; O Learned One!

In assessing the strength of a planet, many methods are used.

There are six kinds of potency in the Sixfold Method. They are

      1) Positional Strength -   Sthana Bala
      2) Directional Strength -  Dikbala
      3) Temporal Strength -    Kalabala
      4) Motional Strength -    Cheshtabala
      5) Natural Strength   -    Naisargikabala
      6) Aspectual Strength -  Drik Bala

The calculation of each of these involves a fairly good knowledge of
astro-mathematical principles.

Application of the Sixfold Strength or Shad Bala

The aphorism " A strong planet will do good; a weak planet only harm " rules Astrology. It is common sense that weak planet weakens the houses he owns & the significations which he signifies.
A planet's strength and weakness is measured numerically by the Shadbala Method. In short, Shad Bala method is the base of Vedic Astrology, as astrologers check the strength and weakness of a planet via the Sixfold Method.

Vedic Astrology Lesson 33,,hindu astrology software, research and consultancy

1) Positional Strength ( Sthana Bala )
A planet may be placed in inimical, neutral or friendly houses. It may be exalted or debilitated. If he be in an inimical house, he is considered weak and he is powerful if in a friendly house. This potency is known as Positional Strength or Sthana Bala.
Positional Strength consists of 5 major factors

1) Exaltation Strength                                 ( Oocha Bala )
2) Strength in the Sevenfold Division          ( Saptavargaja Bala )
3) Strength acquired in Odd & Even Signs  ( Ojayugmarasyamsa Bala )
4) Angular Strength                                     ( Kendra Bala )
5) Decanate Strength                                  ( Drekkana Bala )

The strengths of planets are measured in Rupas. A Rupa consists of 60

1) Exaltation Strength - Occhabala
Occhabala is the Exaltation strength. For instance,the largest planet Jupiter is deeply exalted at 5 degrees Cancer. At 5 degrees Cancer, Jupiter attains a full strength of 60 Shashtiamsas or a Rupa. All planets have certain Exaltation points ( Oochabhagas ) & Debilitation Points ( Neechabhagas ). 
When a planet occupies its  Oochabhaga, it gets One rupa or 60 Shashtiamsas of Oochabala. On the contrary, when it occupies its Debilitation Point( Neechabhaga ), there is Zero Oochabala. There is a gradual increase of Exaltation Strength from the Debilitation Point ( Neechabhaga)  to the Exaltation Point ( Ucchabhaga ) , until at last the Bala reaches its maximum at the Oochabhaga. Conversely, there is a gradual decrease of Oochabala from the Exaltation Point to the Debilitation Point till the minimum is reached at the Debilitation Point (  Neechabhaga ) .

Deduct the Debilitation Point from a planet's longitude and you get the
Oocchabala. If it is in excess of 180 degrees, deduct it from 360 degrees &
divide the difference by 3. This will give the Oocchabala of the planet.
This is the formula for Occhabala
Oochabala = (Planet's Longitude - Its Debilitation Point) * 60/180
                = ( Planet's Longitude - Its Debilitation Point ) / 3
Relations between Planets
Planets are related to the Houses which they own and which they tenant. They are also related to the 16 types of divisions, Shad Varga  ( known as Divisional Charts ). Amongst the planetary members, certain planets are friends, enemies or neutrals. There are two types of relationships between them. They are natural relationships & temporary relationships.  


Natural Relationships
Planet         Friends                       Neutrals                       Enemies
Sun            Moon, Mars, Jupiter    Mercury                       Venus, Saturn
Moon         Sun, Mercury              Mars, Jupiter                None
                                                     Venus, Saturn    
Mars           Sun, Moon, Jupiter    Venus, Saturn               Mercury
Mercury     Sun, Venus                 Mars, Jupiter,Saturn     Moon
Jupiter       Sun, Moon, Mars        Saturn                           Mercury, Venus
Venus        Mercury, Saturn          Mars, Jupiter                Sun, Moon
Saturn       Mecury, Venus            Jupiter                          Sun, Moon, Mars
Temporary Relationships
The planet in the 2nd, 3rd, 4th, 10th, 11th and 12th houses from any other planet becomes his temporary friend. Those in the rest of the houses are temporary enemies.
Combined or Mixed Relations
When a temporary friend becomes a natural friend, they both become intimate friends. A neutral is the combination of a natural friend & a temporary enemy and vice versa.nA bitter enemy is he who is a temporary enemy plus a natural enemy. When we fuse these principles, we get the following equations.
1) Temporary Friend + Natural Friend     =   Intimate friend
2) Temporary Friend + Natural Enemy    =    Neutral
3) Temporary Friend + Natural Neutral    =   Friend
4) Temporary Enemy + Natural Enemy   =    Bitter Enemy 
5) Temporary Enemy + Natural Friend     =   Neutral
1) Temporary Enemy + Natural Neutral    =   Enemy
Thus, from the above equations, we can evaluate a planet's relations.
2) Saptavargaja Bala
This is the calculation of a planet's stregth in the Sevenfold Division ( Sapta Varga ).
A planet may occupy an inimical Varga ( division ) or a friendly varga (
Mitra Varga ) or a neutral varga ( Samavarga ).

Planet in

Moolatrikona    ( Equal to Exaltation )     = 45 Shashtiamsas
Swavarga   ( Own Varga )                       = 30 Shashtiamsas
Adhi Mitra Varga ( Bosom Friend's )        = 22.5 "
Mitravarga     ( Friends )                          = 15 "
Samavarga    ( Neutral )                           = 7.5 "
Shatruvarga    ( Inimical )                        = 3.75 "
Adhi Satruvarga    ( Bitter inimical )        = 1.875 "

Take a planet & examine its relationship with the Lords of
the Sevenfold Division ( Saptavargas )  If in Rasi , if it occupies a
Swavarga ( own Varga ), assign a value of 30 Shashtiamsas; simi-
larly for all other Vargas, assign values based on the relationship
which the planet bears to the divisional lords and you will get the
Saptavargaja Bala or the planet's strength in the Sevenfold