郭嘉
The "Fu Zi" recorded a detailed conversation between Guo Jia and Cao Cao, in which the former carefully pointed out ten advantages the latter had over Yuan Shao. Cao Cao asked Guo Jia, "Benchu (Yuan Shao) rules Ji, Qing and Bing provinces and has vast territories and large numbers of troops under his command. However, he has also been making offensive moves. I intend to attack him, but my forces are weaker than his, so what should I do?"