Ashtakavarga is an intricate method to determine the auspiciousness of the transits. It helps to understand for each Graha which portions of the 360 degree zodiac will be favorable and unfavorable for a particular person.
The basic principle in Ashtakavarga is that each Graha in the natal chart acts like a lagna, and that the 12 houses can be counted from that Graha. Transitting Grahas pass through those 12 houses as counted from each of the natal Grahas. A number of tables detail for each natal Graha-transit Graha combination, which houses are favorable and which are unfavorable. Excluding Rahu and Ketu, but including the Ascendant, that gives 8 Lagnas to count from. A favorable place is marked with “Bindu” and an unfavorable place with a “Rekha”.
Every sign the transitting Graha could pass through is rated for all these 8 lagnas, getting a score between 0 and 8 Bindus. A sign with a score of 0 bindus would mean that the sign is in an unfavorable house position from the Lagna and all of the 7 natal Grahas, and the transit is highly unfavorable. In the other extreme, a sign with 8 bindus is favorable from all natal positions and the transit will be most favorable. The pattern is unique for each transitting Graha, so one and the same sign may be favorable for one but unfavorable for another Graha.
When a table is made for a Graha in transit, showing the individual bindus for each sign from each natal Graha, it is called Bhinnashtakavarga. Bhinnashtakavarga for all the seven planets and the Lagna (ascendant) has been depicted in the Bhinnashtakavarga #1 and Bhinnashtakavarga #2 reports. When the Bindus are added up per sign, giving a score of 0-8, it is called Sarvashtakavarga.
Finally, one can add up all Sarvashtakavarga scores for a particular sign, and get a score up to 56. This is called Samudayashtakavarga. It has been depicted in the Samudayashtakavarga report. A high score in samudayashtakavarga means that the average transit will be favorable in that sign. Because that sign also corresponds to a particular house in the natal chart, the corresponding house will be favorable as a result of “hosting” all those favorable transits.
In summary, the purpose of Ashtakavarga is to identify favorable and unfavorable transits. As an extra feature it can be used to evaluate the auspiciousness/strength of the houses. Even though the bindus as obtained from the 8 points of reference are added up to one score, Ashtakavarga does consider them separate as well. Each sign is divided in 8 equal sections, “kakshas”. Each kaksha is ruled by one Graha, in the order from slowest to fastest velocity. The first kaksha is ruled by Saturn, and when the transitting Graha passes through this kaksha, the bindu (or lack of bindu) as per the house position relative to the natal Saturn is felt. When the Graha passed through the second kaksha, ruled by Jupiter, that time will be good or bad according to the house position relative to natal Jupiter.