The four most importat divisional charts are D-1 (Rasi), D-9 (Navamsa), D-60 (Shashtyamsa) and D-10 (Dasamsa). Aside from planetary placements, what is most important is that the signs overlaying these four charts must be synchronised in such a way that they are overlaying in the correct houses. This would then produce the requird MAGNIFIED effects.
Hence people who are born a few minutes difference, even their planetary placements are the same, or their Rasi charts are similar, can have different fates and fortunes.
How must the synchronicity amongst the 4 charts be evaluated?
(1) General Rule is that the SAME triplicity of the signs overlaying the D-1, D-9, D-60 and D-10 must either be on the trinal houses or earth houses.
(2) Point (1) is only a general rule.
(a) For D-1, the triplicity of signs mentioned can overlay the earth or trinal house.
But overlaying the trinal house would have a better edge provided it is connected to the Earth Houses through planetary lordships (the Water and Earth Ascendants) or planetary placements.
However, if the triplicity of signs concerned is overlaying the earth houses without any relation with the trinal houses either through planetary lordships (the Fire and Air Ascendants) or planetary placements, it does give a person able to fructify whatever efforts he has put in to his work in this world but diligence is required as luck would play a minimal factor.
(b) For D-9, it is better the triplicity of signs mentioned be overlaying the trinal house for luck (D-9 is luck, so cash in on it).
(c) For D-10, the triplicy of signs mentioned should overlay the earth houses (D-10 after all is a career house).
(d) For D-60, the divisional chart of Karma, if the triplicity of signs mentioned is overlaying trinal houses, the person's life is made smoother overall in whatever he does as indicated by D-1, D-9 and D-10. If the sign concerned is overlaying earth houses, it gives a more telling sign of the person's material success in his current life.