These are some of the considerations:-
1. Both use the lowest common denominator: Yin and Yang with The Five Elements concept.
2. Ba zi and Zi Wei Dou Shu can be as general or can be as detailed: thus sometimes; even no two ba zi analysis could beconsidered as equal.
2.1. For example, ba zi can be as detailed as possible: with as many variables in it: Year , Month, Day, Hour and for the living two more pillars : House of Life and House of Conception. (Each variable has two other variables: Heavenly stem and Earthly branches).
3. In my opinion, one should instead, firstly note what is the difference between A's analysis of Zi Wei Dou Shu vs B's, C's or D's! And what is the difference between E's, F's and G's analysis of Ba zi. Since they are often not "created" equal.
4. Fundamentally; some of these terms may apply: W.Y.S.I.W.Y.G (what you see is what you get) and G.I.G.O. (Garbage in garbage out) type of senarios. For example, Ba zi can be as "limited" as just using the Year, Month, Day pillar (especially if Hour, house of life and house of conception) are left out.
4.1. Thus, one cannot say that two ba zi charts are similar! The generic name: Ba zi is the same but how to equate the result of two ba zi findings if one uses only variable as mentioned under Para 4 above vs another that uses ba zi findings based on Para 2.1? Think about it...

Quote

On 9/21/2010 11:27:02 PM, Anonymous wrote:
For BaZi and Zi Wei Dou Shu
would readings of twins be the
same/similar even though one
is male and one female? If
not, would it be very
different and in what aspects?
Thanks

For BaZi and Zi Wei Dou Shu would readings of twins be the same/similar even though one is male and one female? If not, would it be very different and in what aspects? Thanks