To reply to Ms. Hamilton -
TH: Do you mean the Vimshottari dasa system applied to the tropical zodiac? (This would make an interesting discussion on Sam Geppi's new forum if you're interested.)
I didn't mean the Vimsottari - that dasa is measured by the Moon and the nakshatras, and is by necessity based on the ayanamsa, not on the equinoxes and solstices - the Narayana dasa is one of the Rasi Dasas of Jaimini, and sign-based - there is a complete exposition of it in chapter 18 of "Vedic Astrology, An Integrated Approach" by P.V.R. Narashima Rao - he also has a free program available for download which is, IMHO the best of it's type available. Anyway, when I redo this dasa in the Tropical system (thanks to his program, I wouldn't bother if I had to do this by hand) and compare it with my natal chart, not only does everything work out by standard dignity, but it works for the lots as well -
For instance, (all things forward are tropical) I have the lot of Eros in Scorpio, with Selene and Zeus, and Horoskopos is Libra. When I was married, the pattern (from the main period down 4 levels) was Aquarius, Leo, Taurus and Aries - (Aries is the 7th house). All of them are in pivots to Eros except for Aries (this is not an uncommon pattern for signs to take in a key event using Aphesis or annual profection) - but Aries is the natural 7th place of my chart. Ares (Mars), the domicile lord of Eros and the 7th topical place, exchanges signs with the Moon from Cancer, from where it can see both of its domiciles. All these signs except Leo can be seen by their domicile lords, but Leo is, again, in a pivot from Eros (and both Eros and its domicile lord can see Helios, and in the case of Ares, there is testimony. Interestingly, the Lot of Fortune is in Sagittarius, which puts Eros in the 12th from it, but that has special meaning to the way this worked out - I often tell the story that on the previous birthday I had examined my Solar Return for the year, and said "if this were anyone but me, I'd swear they are getting married this year" - I had forgotten that interpretation completely until I dug the chart out of a drawer to elect a wedding date - 12th indeed! But Fortune has its own story to tell about marriage through Aphesis etc., and Eros is seen by its lord, who happens to be lord of the 7th as well - anyway, I've seen maybe a hundred cases of how this dasa works really well tropically, using the system of Hermes. Oh, by the way, if I work this out for the time of the wedding, the 5th level image was Sagittarius - home of Fortune.
And yes, I recognize the value and use of precession, as you know, I have lectured on the subject many, many times. I use it to work to work with my strict and phenomenologically oriented system of transits and certain types of return charts, and usually consider precession on an individual basis rather than as necessitating another zodiac. I do believe that it is a viable idea to base a coordinate system on some star or another (personally, I like Fagan's idea of using Aldebaran rather than Spica) but I think a lot of unnecessary confusion and quibbling can exist when trying to mix systems, and I hold to the premise that the 12 signs that we know and love get their attributes from the Thema Mundi, which is, in essence, a tropical construction. There are excellent books on the attributes of the sidereal "signs" (the New Instant Astrologer, the Solunars Handbook etc.) which can be helpful for those studying the works of the western sidereal movement and wanting to stay consistent (or introduce the concept of precession to the client in a very heavy-handed way).
I have not done enough work with Transits in the Hellenistic system to make an argument for the application of precession to the ingresses of the signs - the 1st degree of an image in the birth horoscope will have changed considerably by the time someone is 35, and that can make quite a difference in timing for the ingress of Saturn (if, in fact, the relationship to the fixed stars is important at all for this method). It's part of what I am studying now, when I have time. I do not consider transiting planets to natal planets important enough other than in the context of the return charts. As far as returns go, I will admit that I currently use the quotidian methods of progression of natal and return charts, and would never use that system without precession, because we are using the movement of the celestial sphere to let us know when the planets are "in the zone". I look at the returns done in the Hellenistic style and follow a little of what Abu Mashar was talking about, but I am missing the first book of that series, and therefore have too little material to base an authentic methodology on.
Anyway, I've got so much work to do right now that I'm going to miss the "Twelfth Parts" intensive this weekend, and have to type with a towel over my hands to keep the tears out of the keyboard. I understand and vibrate with Mr. Noblehorse on the excitement with which I am integrating this teaching into my practice, and, Ms. Hamilton, it was you who introduced me to this work those many years ago -