Why to calculate Vimshottary Dasha System using only Moon Degrees?

Why to calculate Vimshottary Dasha System using only Moon Degrees?

We all know that Vimshottary Dasha System is the most popular Dasha, especially much applicable in this Kaliyuga.

In this system, we calculate Dasha balance using the degree(sphuta) of Moon, and able to find out Dasha Lord and Bhukti Lord. Then we say, at the birth time of an individual Moon is in a particular Dasha and in a particular Bhukti. After that we try to progress the degrees of the Moon to present day, and able to say that at present that individual in a particular Dasha and particular Bhukti and we try to predict some events by checking how  those Dasha and Bhukti Lords are placed in the Kundli of that individual.

Now the question is, can we find similar Dasha and Bhukti Lords of other planets also using their degrees ? Can we find Dasha and Bhukti Lords using degrees of Ascendant and other Bhavas(Cusps) also, and can we similarly progress them to present day and predict something? If yes, then why our rishis mentioned to calculate Vimshottary Dasha using only the degrees of Moon? Is something missing here?

Crude oil

Crude oil :

Slow moving planets Saturn and Ketu entered watery signs of Scorpio and Pisces in 2014 and triggered fall in #crudeoil. This fall is intensified when Saturn entered Anuradha nakshatra in Scorpio and Ketu entered Uttarabhadra nakshatra in Pisces. We know that both these nakshatras are ruled by Saturn. Saturn in a watery sign of Scorpio ruled by Mars and  in its own star of Anuradha is certainly an agent of crude oil. These two slow moving planets created more fall in crude oil prices during their transit in nakshatras ruled by Saturn.

Now in the first week of Dec, 2015 one of  these slow moving planets is leaving the nakshatra ruled by Saturn. Ketu is leaving Uttarabhadra nakshatra.

So I feel worst is over for  #crudeoil prices and I see no further fall, should be  bottom out very soon.