Wu Qingyuan's study of the effectiveness of stones was the basis of his famous saying "Baduk is harmony." More specifically, he said "Balance is the harmony of the stones on the board, and the practical use of their placement." According to Wu Qingyuan, thickness and influence constitute one important dimension of this balance. This is a crucial point in understanding the power of Wu Qingyuan's Baduk.

It should be remembered that the development of a methodical theory was one of Wu Qingyuan's greatest accomplishments. His efforts to overcome the limited use of stones and maximize their practical use was successful. Moreover, his balance theory was not the result of genius alone, but the fruit of his continuous study.
Wu Qingyuan taught us how to develop the art of Baduk. We now look out on the Baduk world from the great height of his enormous shoulders.

- by Moon Yong-Gik, 4-dan