I found this article on Elsa’s Astrology News feed from astrologer John Marchesella who equates the :
We could tell you in no uncertain terms that knowing the math by heart really does explain a lot of the astronomy of astrology. We can also assure you that a professional astrologer feels more solid with the chart, so to speak, when he or she knows where all the parts of it come from. (I heard Rob Hand once say that calculating the horoscope by hand is the astrologer’s “yoga” with the interpretation of it). And finally we can hope that the math will back up your performance with clients, especially the suspicious ones who like to pull the trivia quiz on the science of the chart.
That’s all true, but you know what? After all these years of learning, teaching and practicing, I really think it is about eating your spinach, and it’s the spinach that really counts in a good reading with a client. Call it character-building, call it grunt work, call it a lesson in compassion for your client’s hassles, or just call it the math of the chart. I say it’s spinach and it’s good for you.
I support the concept of certification in theory, but the idea of going back and learning how to cast a chart all over again after nearly 30 years is a daunting idea. I began studying astrology around 1980 which was long before computer programs were around, and I like everyone else learned how to cast a chart by hand. The process of casting a chart took about an hour, but by the time you were done you really understood the chart. I used to love drawing the symbols in the wheel, that may have been my favorite part! It felt so magical.
At least I had atlases and house tables; there was a time when even that information was not so readily available. Now anyone with an internet connection can download a chart thanks to the generosity of astro.com and other programs, a factor which has spawned a huge number of people calling themselves astrologers. Astrology is a Uranian field of study, and it is therefore difficult to apply a structured set of rules. Still, astrology is an art of infinite magnitude, and it benefits all of us to continue to study, take classes, and know how to cast a chart by hand. After all, if we are forced off the grid some day we may need to!