Xi Zhicai

Guo Jia (170–207), courtesy name Fengxiao, was an adviser to the warlord Cao Cao during the late Eastern Han dynasty of China. Throughout his 11 years of service, Guo Jia aided Cao Cao greatly with his brilliance and foresight, and his strategies were instrumental to Cao Cao's triumphs over rival warlords such as Lü Bu and Yuan Shao. For example, four years before Cao Cao's decisive victory over Yuan Shao at the Battle of Guandu, Guo Jia already foresaw that Cao Cao would win when he pointed out ten advantages Cao Cao had over Yuan Shao.