Note:  This blog was written on Jan. 21, 2004

In the last 12 months or so, there seems to be a "Xuan
Kong Da Gua" (XKKDG) "gold-rush"--- for the FS
marketers. Almost everyone is itching to set up XKDG
class of some sorts. XKDG classes are normally around
5 days in length, with a dose of I-Ching class as

To keep this discussion simple and as unbiased as
possible, I won't argue whether XKDG theory is valid
or not and working or not. I just examine it from a
scientific and methodological point of view.

As I have written previously, the history of luopan
development is a progression of from simple to
complex. Early luopans had few divisions, then 24
mountains, 60 dragons (divisions), 72 dragons, 120
dragons, 240 dragons and then up until now, 384 "yaos"
(that is 64 hexagrams x 6 yaos).

XKDG has 64 hexagrams which occupy 5.625 degrees each.
Each hexagram has 6 "yaos" (yin _ _ yang __ symbols)
with each yao taking up 0.9375 degree.

Then we may ask, how precise luopan measurements were
when the XKDG theory was developed 4- 500 years or so
ago? Afterall, it is rumoured that Master Jian Da
Hong hinted he had used XKDG principles in his trick
songs (poems). It is also rumoured that Master Shen
(author of "Shen's XK Studies") had "almost" included
XKDG in his book except he had missed the deadline.

An excellent source of info about luopan history can
be found in Professor Chen Jian Jun's book, "Chinese
FS Compass" (ISBN7-5390-1430-x/K.5, available in
Chinese or English). In this book, it seems luopans
made during Ming Dynasty (1368- 1644) were mostly
"water compass" (using a floating needle) and both
"water" and "dry" compasses were used during Qing
Dynasty (1636- 1911).

How precise could an ancient "floating needle" be?
How accurate will be the needle of an ancient luopan?
Could they measure down to 0.9375 degree consistently?
If not, how could the ancient masters verify their
XKDG theory?

Using modern luopans and compasses as guidance, we
could see it is very doubtful that XKDG measurement
could be achieved by the ancient masters consistently.

According to Professor Vic Schmidt,(Dept. of Geology &
Planetary Science, University of Pittsburgh), even
modern precision compasses like the Brunton or Suunto,
has problem to attain accuracies of better than one

So how about about our modern luopans? It is common
knowledge that even the best branded luopans are
accurate to at most plus or minus one degree. This
will either "hit' or "miss" a DG measurement of 0.9375

For the sake of discussion, let's assume the ancient
masters could consistently do DG measurements down to
0.9375 degree.

To keep it simple, let me quote Professor Schmidt

"I maintain that anyone who claims to be able to
attain accuracy to better than 0.6 degree in a magnetic
survey is deluding themselves.

As I pointed out a while back, failure to keep track
of the long-term secular variation in Earth's field
can easily throw you off by much more, with it
amounting to up to 0.2 degree per year in many places.

And it is strictly cumulative, so if you use
10-year-old map data, you can easily be off by a full
degree (all the time!)."

We know in flying star there is 24 mountains and each
mountain has 15 degrees to "play with". So assuming
your orientation is not too close to the borderline
(or void line) with another mountain, the changing
of the earth's magnetic field by one or two degrees
over the years won't "throw" you out of the mountain.
Flying Star has pretty good tolerance on the earth's
magetic variations.

At 0.2 degree cumulative variations per year, a DG
measurement of 0.9375 degree can be easily become
invalid in a few years. Then this would have been a
lot of testing for the ancient masters. How many
lifetimes could they have in the last few hundred
years to do testing?

You have to make your own conclusion whether the
ancient masters could have done sufficient DG
measurements and testing of XKDG theory, given
the ancient "water" and "dry" luopan technology.

Could you do consistent DG measurements with modern
luopan and compass?

How XKDG handle earth's magnetic variations?

In simple terms, is XKDG practical? Is it just
another case of "misplaced precision"?

My sifu taught me XKDG in 20 minutes. I'll teach my
students how to use it in 5 minutes, if they want to
learn it. It is not difficult to integrate XKDG into
the popular Flying Star method.

Personally, I won't write off XKDG, but I won't spend
too much resources on it either.

Postscript: Now is August 2007, XKDG is not as "hot". But there is still a new one coming out recently charging
US$1900 for 2 days of class. It's ad sounds like magic-- you can get whatever you want with it.

Ken Lai