„The theory of the Korean style is that the key to the game is fighting. Territory should come from fighting because then it is the most secure. Territory that is made without fighting will have weaknesses that you must worry about and fix later. Everything gets played out in fighting so there are no lingering uncertainties that must be dealt with, no potential life and death problems, no aji hanging over your head. Fighting is the essence of go.“
Yuan Zhou, in „Master Play: The Fighting Styles of Kato Masao and Seo Bong Soo“