Deals with transit or Gochara of Grahas (Planets) in Bhavas (Houses). It has less significance in natal chart interpretation and Mundane Predictions and timing of events.
The principle of this system is as follows :
Grahas transition in a sign.
Each sign is divided into 8 kakshas or parts.
Each Kaksha is 3 deg 45 min. For 8 kakshas the total is 30 degrees of a sign.
Each Kaksha is ruled by a Graha.
The sequence of Kakshas are Shani (Saturn), Guru (Jupiter), Kuja (Mars), Surya (Sun), Shukra (Venus), Budha (Mercury), Chandra (Moon) and Lagna. The sequence is mathematically based on the decreasing order of the time taken by the grahas, to transit a sign.
Rahu and Ketu move in retrograde motion and not taken for positive Mundane Predictions in Ashtakavarga.
Each house of a Graha and Houses gets benefitted or strength.
Ashtakavarga is done for each graha and also a cumulative Ashtakavarga called Sarva Ashtakavarga. The total sum of Sarva Ashtakavarga on all 12 bhavas is 337.
To start with
Use a good Astrological software to make your Sarva Ashtakavarga for your birth chart.
Mark the natal chart, starting from Lagna as 1 till the 12th house for Sarva and graha Ashtakavarga charts.
In the Sarva Ashtakavarga, note down the houses which has maximum and minimum bindus. Also in the graha Ashtakavarga charts.
The lowest bindu house indicates problems in the natal chart.
Weakest house is the one which has the lowest bindu and less than 25 bindus.
Medium houses are with equal to 25 till/equal to 28 bindus.
Strong house constitute greater than 28 bindus.
Strongest house has the highest bindus and greater than 28 bindus.
The highest bindu house makes that house significances strong.
Example : I have 36 in 11th house, which is house of profits. And in 12th house, which is 32. So good earning and good spending and with good savings of the left over.
I have 33 in 1st house. A self made person with a strong mind.
Pros of Ashtakavarga
It is a quick way to assess a chart.
Gochara can be read, with the bindus of the house, graha transiting it.
Cons of Ashtakavarga
It cannot tell the event that will happen.
It cannot tell the time of the event based on the chart, namely using Vimshottari Dasha or any other.