Compatibilty cannot be assessed by simply saying one sign is good for another. If this were so, there would be no need for drawing natal charts and no need or benefit to astrology that operated above the understanding ability of elementary school children.
I have been doing astrology for 50 years and I specialize in relationships. I have seen that the general rules that teach that "Earth and Water signs are best with other Earth signs or Water signs" and "Fire and Air signs being compatible with other Air or Fire Signs" are so general as to be useless. I have seen some of this type of compatibility showing up with the Rising signs in long-standing relationships but I have nor seen it hold any water for Sun signs.
What I have seen is that the composite chart is the best predictor of longevity - and I would assume that means best indicator of compatibility as most people understand it. Synastry can give important clues to the specific dynamics that cause friction or dissatisfaction (and what can be done about them) and areas of harmony and ease. But it will not predict if the two individuals will stick it out over the long haul.
I have seen many, many long standing (30 years+) marriages that appear to be healthy relationships where the Sun signs of the two partners were in consecutive Sun signs. This tends to produce a composite chart with a stellium of the personal planets which, if it is well aspected, is a very positive indicator of attraction and longevity. There are about 3 other aspects in the composite that come up again and again in long-lasting marriages.
Barb at
thelivingsky@wordpress.com