1. I believe that what you are inquiring about is quite "academic". 2. To be honest, there will be an endless debate regarding the merits of one method over another. 3. In my view, having numerous clients; some of whom have sought earlier consultations with different practitioners and second opinions; I have come across various charts. 4. From my understanding, among the practitioners in Singapore; many utilize the Pie chart method, myself included. 5. Why? 5.1. The Pie