The information about this method of progression can be found in the last part of the chapter on Sudarshana Chakra in "Brihat Parasara Hora Sastra" (BPHS).
The method is very simple being a kind of Rasi Dasa, giving one year for each sign starting either from the Janma-Lagna, the Chandra-Lagna or the Surya-Lagna so that we get the same sign once in every 12 years.
According to BPHS these progressions should be based on the three different Lagnas mentioned above. However, I have tried to use Chandra Lagna as suggested, but this sometimes gave mistakes. Surya-lagna has given me the best results.
The Sudarshana Chakra as described in BPHS is a kind of graphic representation of three different charts seen in one chakra for better overview. The three charts are:
1) Janma-Kundali (from the Ascendant)
2) Chandra-Kundali (from the Moon-sign)
3) Surya-Kundali (from the Sun-sign)
By making these three charts in three circles within each other, and keeping the first house at the same place, it is possible to see the house positions the planets in all the three charts within the same Chakra.
However, I do not use this type of Chakra, because I prefer the
South-indian method of drawing the horoscope, where the above three charts can be seen very easily in one and the same chart.
In BPHS it is clearly stated that this method should be used side by side with the Vimsottary dasa. But whether Parasara actually combined the two methods is a different matter. I have seen no direct sloka in support of such a statement in BPHS. Perhaps we will have to find out ourselves if it works or not.
According to BPHS it is also possible to divide each year into twelve months each represented by a sign. Following the same principle the months can be subdivided into twelve 2½ days periods, and these 2½ days periods can by further divided into even smaller fragments.
Some information about Sudarsharna Progressions can also be found in a Sanskrit-text called "Sanketanidni" by Ramadayalu to whom this was one of the finest secrets.
The method is also used in connection to Varshaphal (Solar Return Charts) by the Tajaka-school (muslims) under the name Muntha, and as such one can read about it in many standard textbooks on Tajaka. But it is obvious that these authors have not at all realized how important this method really is. It is my impression this method is merely being used as a kind of extra Ascendant for Varshaphal by the followers of the Tajaka-school.
The ancient Greek and Roman astrologers also knew this method, and an ancient text called "Mathesis", by the Roman astrologer Julius Firmicus Maternus from the 4th century AD, gives a lot of information about it.
It was obviously a very important part of the predictive methods at that time. The Greeks however only used the rulers of the signs and not the signs themselves for their predictions. They believed that only the planets themselves – not the signs - could become rulers of time.
Later on this method was used widely by astrologers from the Medieval and Renaissance era like Tycho Brahe, John Dee and William Lilly, who usually referred to it as Profections.
I only calculate the Sudarshana-progressions from the Ascendant if I am absolutely sure the Ascendant is correct. The Ascendant can however be verified using this method on known events in the past.
Today I think only very few astrologers have realized the predictive importance of this method and just how useful it actually is for astrologers having daily consultations.
The method is very fast and easy to use. Very often one can read the results directly out of the horoscope. But it still needs at lot of astrological knowledge, experience and good judgement on the part of the astrologer practising it. The method is not at all some automatic self-predicting oracle. It is only as good as the astrologer using it.
The best thing to do is to study carefully the books like BPHS as to which houses and yogas are connected to what kind of events or subjects. Then one has to collect a number of practical horoscopes related to the same event or subject to actually find the common factors or precise planetary patterns for this or that event. This is a very educative and interesting research.
It is my impression this method indicate the totality of trends available in a given year, but the precise planetary indicators are pointed out by the degreewise transits of Saturn, Jupiter and Rahu.
Mr. K. N. Rao has kindly suggested to me that this method be called Sudarshana Chakra Progressions, since it is described in the chapter on Sudarshana Chakra in BPHS.
During the years I have got many useful hints on predictive methods like this one. In some cases from a book, from an article or from some old and experienced hindu astrologer. Astrologers very often leave behind small, useful fingerprints like that.
On November 20th we had general elections here in Denmark, and there were two candidates running for Prime minister. There was the previous Prime minister, Mr. Poul Nyrup Rasmussen seeking re-election and a new candidate for Prime minister, Mr. Anders Fogh Rasmussen.
I was able to predict the outcome correctly using Parasara's Sudarshana-progressions combined with the degreewise transits. It was however not a public prediction, but only given in front of a few astrologer-friends. Anyway, here is my judgement:
1) Poul Nyrup Rasmussen, aged 58
Asc 18:56 Ari
Sun 00:02 Gem
Moon 17:10 Lib
Mars 20:39 Pis
Merc 07:39 Tau
Jup 03:38 Can
Ven 14:52 Can
Sat 23:55 Tau
Rahu 24:23 Can
Ketu 24:23 Cap
Candidate No. 1 has got Surya-lagna in Gemini, and counting one signs for each year upto his age of 58 we get Aries. So please look at his chart from the Aries. There are no powerful Raja-yogas.
The first-lord Mars is in the 12th house and natural malefic Ketu is in the 10th. This indicated a situation of Moksha... It shows someone who is being retired, applying for pension or perhaps going for a long vacation - anything but becoming the prime minister.
On the date of the election Jupiter was transitting at 21 degrees Gemini in exact square to his Mars in the 12th.
2) Anders Fogh Rasmussen, aged 48
Asc 16:36 Lib
Sun 12:35 Cap
Moon 28:24 Tau
Mars 26:54 Aqu
Merc 07:12 Cap
Jup 18:30 Ari
Ven 29:23 Aqu
Sat 03:59 Lib
Rahu 19:12 Cap
Ketu 19:12 Can
Candidate No. 2 has got Surya-lagna in Capricorn, so by counting one sign for each year upto age of 48 we get Capricorn. From Capricorn we have the 1st-lord, Saturn exalted in the 10th making parivatana yoga (mutual reception) with Venus in Aquarius. Obviously there is a wealth of powerful Raja Yogas, and therefore he was elected the new prime minister.
On the date of election Rahu was transitting at 3 degrees Gemini in excact degreewise trine to his exalted Saturn and thereby triggering the event.