https://www.youtube.com/watch?v=tyzkh1y4DF4&t=5724s https://www.youtube.com/watch?v=tyzkh1y4DF4&t=5724s a video of PVR Narasimha Rao a very respected astrological researcher, he does not do any consultation he makes his living as a corporate computer engineer, he showed a successful method of predicting about 285 year cycles of history without any kind of need of accurate birth time for a nation you just use the capital location and the conjunction of Jupiter and Saturn when Ketu is in Pisces. if the theory that Yuga change happening now is not correct then he may have the best method of prediction of long term trends. it depends mostly on the region you are in, as when the chart changes the appropriate dasha system might not be vimshottari, but as most will use vimshottari and he says USA and China charts do therefore it indicates the next 16 years are warlike with competition between different countries for dominance and out of it the current chinese government collapses due to dissatisfaction with governance and also the USA remains relatively powerful but loses its pre-eminent position hat it has now.