As the most outstanding counselor of Cao Cao Group, Guo Jia's greatest role is not only to make suggestions, but more importantly, to make a situation analysis for Cao Cao when he is confused and difficult to make decisions, so that he can make clear his strategic goals and take decisive tactical actions. Cao Cao had two biggest doubts in his early years. First of all, Yuan Shao's military clique caused him great psychological pressure. The second is that there were many warlords in the north at that time, and they were worried about the power behind every move. At this critical time, it was Guo Jia's analysis that got Cao Cao out of the state of anxiety and doubt.
After Guo Jia's death, Cao Cao's campaign was no longer as smooth as before. No matter the battle between Battle of Red Cliffs and Ma Chao, or the battle between Hanzhong, they all stumbled, especially Battle of Red Cliffs, which happened in the second year after Guo Jia's death. The failure of this campaign proved Guo Jia's supreme position among Cao Cao's counselors.