Olympic siver medallist P V Sindhu and former World No 1 Saina Nehwal slipped a place each to be at the fourth and ninth spots respectively in the latest BWF World ranking released .Both Sindhu and Saina last played at the Asian Badminton Championship in China with the former losing in the quarterfinals, while the latter bowed out in the first round.In men's singles, Ajay Jayaram continues to be the best- ranked Indian at the 13th spot, while Sai Praneeth ranked 22nd.