Sudarshana Chakra is a wonderfully simple and accurate predictive technique presented in Brihat Parashara Hora Shastra. Three charts are erected, one inside the other. The outer chart starts from the Sun, the middle chart from the Moon and the inner chart starts from the Lagna. These three charts are arranged so that the Sun, Moon and Lagna are all situated at the first house, which is the top of the chart or on the left depending on which option you prefer (It is at the top in the screenshot below). Around each chart are the transiting planets. On the lower left is the Sudarshana Chakra Dasa, with each house having a Dasa of 1 year, starting at the first house. The transiting planets are updated for whichever Dasa you click on. Looking at the positions of the transiting planets in the Dasa houses easily reveals the events to come.