 Complete the following phrase:  Chen rated among the worlds leading singles players when China entered the International Badminton Federation now Badminton World Federation in 1981. The powerful Changjie won the first major IBF sanctioned tournament in which China participated, the multi-sport 1981 World Games in Santa Clara, California, by successively beating Prakash Padukone and Morten Frost in the semifinal and final rounds. He helped China to win the 