The traditional system, which is ashtkoot, is based on the birth constellation, rashi and rashi lord of moon and characteristics of each constelltion and its positional aspect with respect to other. In south dashkoot methodology is used which is a further extension of the same.
The points which are taken into consideration, in ashtkoot method, are :
1) Varna: It is the classification of community of rashis, just like we have Brahmin, kshatriya, vaishya and shoodra same goes with rashis. The best combination is when both are of same varna.
2) Vashya: It is the division of rashi`s on the basis of their nature i.e. two legged, four legged, and jala(watery). Here also it is best to have both with same vashya.
3) Tara: It is based on constellation and specific position of birth stars of both are considered to match each other. They are total 9 in number .
4) Yoni: This is seen for sexual compatibility between the boy and girl. All constellations are assigned certain animals for male and female constellations and the match is based on it. Marriage between nakshatras of same class of yoni and between male and female constellation of that yoni is considered best.
5) Grahmaitri: The sign lord of moon at birth is seen, moon is the karak for mind and its lord is takes for reference to gauge the mental compatability between the two. If the lords are good friends then full points are allotted.
6) Gan: All the 27 constellations are divided into 3 types of intrinsic characteristics called as DEV, MANUSHYA AND RAKSHASA. Rakshasa can only marry a rakshasa and rest of the two can marry each other but the best combination is when both are same.
7) Bhakoot: It is the distance between the janma rashi of the boy and girl and the result is derived after considering it.
8) Nadi: This aspect signifies the pulse or the nervous energy indicating the physiological and some hereditary factors. The boy and girl should not have same nadi.
Apart from this there is Mangal Dosha to be considered very seriously for a prosperous marriage. This one factor can eliminate all the good factors present in a match result.
There are free and paid softwares available in the market which can calculate all this in a fraction and tell the result. But the result is not satisfactory…all the 8 points I mentioned above are based on moon and its constellation at time of birth.
In this method, the most important are yoni, grahmaitri, gan match. These three should be having full marks or atleast next to full marks otherwise one should not go ahead.
But a person always grows up and dies one day, he or she does not remain in that constellation for the all their lives and this is the biggest drawback of this matchmaking. In my opinion, the prevailing dasha of both, the position of ascendants, the position of sun, Jupiter, Saturn, venus is of more importance than this ashtkoot or dashkoot method which is based upon something that happened years ago in the life of a native.
The position of these planets should not be 6-8 or 2-12 to each other, the ascendant and 7th house should have least or none malefic aspect and 2nd house should be well enough. These houses should not be in paapkartari and the prevailing and the next dasha lords should be friends or atleast neutral to each other and in good position in chart with respect to each other.
On stellar level, the ascendant should not be connected to 6,8,12 houses in any way so should 2nd 7th 5th and 11th houses.