According to prevalent definition of Sunfa Yoga in Vedic astrology; if in a horoscope, there is one or more than one planet in the house next to the house of placement of Moon, Sunfa Yoga is formed in the horoscope. This Yoga may bless the native with good results related to wealth, fame and many other things.
The placement of Sun, Rahu and/or Ketu only, in the house next to the house of placement of Moon is not considered for the formation of this Yoga. Hence one or more than one planet other than Sun, Rahu and Ketu should be placed in the house next to the house of placement of Moon in a horoscope, for the formation of this Yoga in that horoscope.
In real practice, Sunfa Yoga is not seen producing such results when only the aforementioned conditions are met. Hence more conditions should be met in order for this yoga to be formed effectively in a horoscope. If Moon is functionally benefic in one such horoscope, this yoga may produce better results. If the planet/planets placed in the next house are also benefic; Sunfa Yoga may produce even better results.
Taking an example, suppose Moon is placed in the first house of a horoscope in Sagittarius and exalted Mars is placed in the second house in Capricorn. Moon is malefic in this horoscope. Mars is partly benefic and partly malefic in horoscopes with Sagittarius ascendant. In this case, Sunfa Yoga may not be formed in the horoscope; though the primary conditions are met. The concept of a planet being partly benefic and partly malefic has been explained in the book ‘Pitra Dosh – Ancestors are Calling (Revised Edition)’.
Taking another example, suppose exalted Moon is placed in the first house of a horoscope in Taurus and Mercury is placed in the second house in Gemini. In this case, Sunfa Yoga may be formed in the horoscope, since both Moon and Mercury are benefic. Hence the native with may witness good results related to health, lifespan, education, profession, finances, wealth, family and a number of other things.
Once the formation of Sunfa Yoga is confirmed in a horoscope, the next factor to check is its strength. The strength of this yoga is calculated through the placements of planets involved in its formation in various signs, nakshatras and navamshas; as well as through the influences of other benefic and malefic planets on them. The overall theme of horoscope and running times (Mahadashas) also affect the strength of this Yoga.
Taking an example, suppose Moon is placed in the first house of a horoscope in Taurus, in Taurus navamsha of Rohini nakshatra; and Mercury is placed in the second house in Gemini, in Gemini navamsha of Punarvasu nakshatra. Moon and Mercury are strong in their respective signs as well as navamshas. Hence strong Sunfa Yoga may be formed.
Looking at the running times; when Mahadashas (planetary periods) of malefic planets are in effect; benefic effects of Sunfa Yoga may reduce. When Mahadashas of benefic planets other than the ones involved in the formation of this yoga are in effect; benefic effects of this yoga may increase. When Mahadashas of the planets involved in the formation of Sunfa Yoga are in effect; the native may witness maximum benefits through this yoga. For instance; in the recent example, the native may benefit the most during Mercury Mahadasha and Moon Mahadasha.