This occurs when one of the planets of this yoga is lord of the third house. The other planet may not be lord of the sixth, eighth or twelfth house (because we then have a dainya yoga). The third house is the house of energy and strength. A kahala yoga would mean that the person involved would invest a lot of energy and vigour in improving his circumstances.
Example: If Taurus is on the ascendant, the Moon is lord of the third house and Saturn lord of the ninth and tenth houses. Supposing the Moon is in Capricorn and Saturn in Cancer. Then we have a kahala yoga. This person will put a lot of energy (third house) into his career (tenth house) and into broadening his horizons (ninth house).
Maha yoga: When a parivartana yoga occurs between the lords of the first, second, fourth, fifth, seventh, ninth, tenth or eleventh houses, we have a maha yoga. The lords of the third, sixth, eighth or twelfth houses may not be involved, because then we would have either a dainya yoga or a kahala yoga. This yoga enriches the planets involved.
JV ASTROLOGY 