According to prevalent definition of Chatussagara Yoga in Vedic astrology; if in a horoscope, planets are placed in all Kendra houses (1st, 4th, 7th and 10th), counted from ascendant or Moon, Chatussagara Yoga is formed in the horoscope. Chatussagara Yoga can bless the native with good results related to health, lifespan, profession, marriage, education, money, wealth, prosperity, luxuries, reputation, authority, fame and many other good things.
In real practice, Chatussagara Yoga is not seen producing such results when only the aforementioned condition is met. Hence more conditions should be met in order for this yoga to be formed effectively in a horoscope. Looking at the first condition, at least three Kendra houses should be occupied by benefic planets, for the formation of Chatussagara Yoga in a horoscope. Apart from that; placements of planets in Kendra houses from Moon may not form this yoga in a horoscope. Hence only Kendra houses from ascendant should be considered for the formation of this Yoga.
Taking an example, suppose Saturn is placed in the first house of a horoscope in Pisces, Sun is placed in the seventh house in Virgo, Mars is placed in the fourth house in Gemini and Moon is placed in tenth house in Sagittarius. Saturn and Sun are malefic in this horoscope; and Saturn is placed in the most important house of horoscope; the first house. Hence Chatussagara Yoga may not be formed in this case.
Taking another example, suppose Jupiter is placed in the first house of a horoscope in Pisces, Mars is placed in the tenth house in Sagittarius, Venus is placed in the fourth house in Gemini and exalted Mercury is placed in the seventh house in Virgo. Jupiter, Mercury and Mars are benefic in the horoscope whereas Venus is malefic. Hence Chatussagara Yoga may be formed in this case.
Once the formation of Chatussagara 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 overall theme of horoscope and running times (Mahadashas).
Taking an example, suppose benefic Jupiter is placed in the first house of a horoscope in Pisces, in Sagittarius navamsha of Revati nakshatra and benefic Mars is placed in the ninth house in Sagittarius, in Aries navamsha of Moola nakshatra. Benefic Moon is placed in the fourth house in Gemini, in Taurus navamsha of Punarvasu nakshatra and benefic exalted Mercury is placed in the seventh house in Virgo, in Virgo navamsha of Chitra nakshatra. Jupiter, Mars and Mercury are strong in their respective signs as well as navamshas. Moon may do very well in Taurus navamsha of Punarvasu nakshatra; within the sign of Gemini. Hence strong Chatussagara Yoga may be formed; which may bless the native with very good results related to many spheres of his life.
Looking at the running times; when Mahadashas (planetary periods) of malefic planets are in effect; benefic effects of Chatussagara 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 Chatussagara 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 Moon Mahadasha, Jupiter Mahadasha, Mercury Mahadasha and Mars Mahadasha.