Guo Jia (170-207), whose name is Fengxiao, was a native of Yangzhai (now Yuzhou, Henan). At the end of the Eastern Han Dynasty, Cao Cao was a famous strategist.

Guo Jia was originally a subordinate of Yuan Shao, and later switched to Cao Cao, and made meritorious contributions to Cao Cao's unification of northern China. He died of illness during Cao Cao's expedition to Karasuma at the age of thirty-eight.

The history books call him "a genius and a strategist, a strange man of the world". Cao Cao praised him for seeing people and being his "Qizuo".

Guo Jia was born in Yingchuan, he had a vision when he was a teenager, and when he saw that the world would be in chaos at the end of the Han Dynasty, he lived in seclusion after the weak crown (twenty years old), secretly befriended Yingjie, and did not associate with the world, so not too many people knew about him.

At the age of twenty-one, Guo Jia traveled north to see Yuan Shao, and said to Yuan Shao's advisers, Xin Ping and Guo Tu: "A wise man can measure his master prudently and thoughtfully, so that he can make meritorious contributions and fame." Yuan Gong only wanted to emulate Zhou Gong's Corporal Lixian, but he didn't know the truth of using talents. Thinking and lacking the essentials, liking to plan but not decisive, it is really difficult to save the country from danger and establish the great cause of hegemony with him! So he left Yuan Shao from then on. In this way, Guo Jia has been idle for six years.

In the first year of Jian'an (196), one of Cao Cao's most important strategists, Xi Zhicai, died. In addition to being sad, Cao Cao wrote to Xun Yu and asked him to recommend a strategist who could replace Xi Zhicai. So, Xun Yu recommended his friend Guo Jia to Cao Cao. Cao Cao summoned Guo Jia to discuss major events in the world, and after the discussion, Cao Cao said: "The person who can help me achieve great things is him!" After Guo Jia left the camp, he was also overjoyed and said, "This is my real master!" ”

From then on, Guo Jia became Cao Cao's staff and military officer-the military advisor sacrificial wine, giving advice and serving Cao Cao's Quartet campaign loyally.

At that time, the princes from all walks of life were divided into a corner and fought for the world. In this case, Guo Jia's accurate judgment of the psychological state of each opponent often became the key to Cao Cao's victory.

In the second year of Jian'an (197), Cao Cao begged Zhang Xiu for a new defeat, and Yuan Shao wrote a letter to humiliate. When Cao Cao was worried that he did not have the ability to compete with Yuan Shao, Guo Jia put forward the famous "ten wins and ten defeats" theory. He cited ten reasons in a row to prove that "the public has ten victories, and the Shao has ten defeats." Guo Jia's analysis was very convincing, which not only boosted the morale of Cao's soldiers, but also helped Cao Cao formulate long-term and short-term combat goals. At the same time, Guo Jia also officially established his core position in Cao Cao's military intelligence regiment.

In the third year of Jian'an (198), Liu Bei was broken by Lu Bu and attached to Cao Cao. The strategist Cheng Yu suggested to Cao Cao that he kill Liu Bei to prevent future troubles, and Cao Cao asked Guo Jia what his opinion was, and Guo Jia thought: "Indeed. However, Cao Gong raised his sword to rebel against the army, eradicate violence for the people, and introduced integrity to recruit heroes and heroes, but I am afraid it has not yet been achieved. Now Liu Bei has a reputation as a hero, and he took refuge in us at the end of his rope and we killed him, which is the notoriety of killing the Magi. Then the wise men and soldiers will doubt themselves, and they want to choose who to choose as the master again, so who does Cao Gong want to settle the world with? Therefore, the choice to get rid of one person and endanger the prestige and safety of the four seas cannot be unnoticed! Cao Cao also felt this, so he did not kill Liu Bei. However, Guo Jia also believes that Liu Bei has tens of thousands of enemies Guan Yu and Zhang Fei to follow, and Liu Bei is popular and will not be underwhelmed. Therefore, he admonished Cao Cao: "The ancients said: 'If you indulge your enemies for one day, you will become a disaster for several generations.'" It is advisable to establish a proper position earlier. It means that Liu Bei is under house arrest, but Cao Cao did not accept Liu Bei's scheme, in order to make him convince himself, he became closer to Liu Bei.

In September of the same year, Cao Cao sent troops to attack Lü Bu, who was in Xuzhou. Cao's army first broke through Pengcheng, then defeated Lü Bu, and finally besieged Xiapi. Lu Bu couldn't hold on. The battle lasted for more than half a year, and Cao Cao saw that the soldiers were tired and prepared to give up. At this time, Guo Jia saw an opportunity to win. He used Xiang Yu as an example to advise Cao Cao, and put forward the view that "if those who have courage and no strategy are exhausted, they will soon be defeated", and persuaded Cao Cao to attack urgently. Cao Cao followed Guo Jia's strategy, attacking the city on the one hand, and breaking the embankment to cover Pi on the other, and sure enough, he conquered Xiapi in the same month and captured Lü Bu. In the fourth year of Jian'an (199), Liu Bei took the opportunity of Yuan Shu to surrender to Yuan Shao and took the initiative to ask Cao Cao to intercept the attack. At this time, it happened that Guo Jia and Cheng Yu were not around, and Cao Cao agreed to Liu Bei's request. When Guo Jia and Cheng Yu came back, they dissuaded Cao Cao together after learning about it: "Let Liu Bei go, there will be variables!" But at this time, Liu Bei had left, and seized Xiapi and raised troops against Cao Cao, who regretted not listening to Guo Jia.

In the fifth year of Jian'an (200 years), Cao Cao, in order to avoid being attacked by the enemy in the future against Yuan Shao, decided to first eliminate Liu Bei, who had not established a firm foothold in Xuzhou. At that time, all the generals were afraid that Yuan Shao would take the opportunity to attack Xudu, and when the time came, he would not be able to fight and retreat and lose his stronghold. Cao Cao was also suspicious, so he asked Guo Jia for advice, and Guo Jia analyzed: "Yuan Shao has always been indecisive and will not react quickly. Liu Bei's hearts have not returned, his foothold is not stable, and if he attacks quickly, he will definitely be defeated. And then return to the division to deal with Yuan Shao, this is the best opportunity to change the abdomen and back to the enemy, and it must not be lost. So, Cao Cao raised his army to the east, defeated Liu Bei, captured Liu Bei's wife, captured Guan Yu, and then defeated the East China Sea pirates who were united with Liu Bei. The situation was as Guo Jia expected, and before Yuan Shao could react, Liu Bei had been defeated. Just when Cao Cao and Yuan Shao were holding each other's official crossing, another disturbing news reached Cao Ying: Jiangdong Haojie Sun Ce was preparing to send troops to attack Cao Cao's base in Xudu. Cao Cao, who was already at a disadvantage in the standoff with Yuan Shao, could no longer draw troops to defend Xu Du. And once Xu Du is lost, Cao Cao's camp will immediately fall apart. This was the most turbulent period in Cao Ying's people's hearts, and many people began to secretly flatter Yuan Shao, preparing to leave a way back for themselves.

At that time, Cao Junzhong and Yuan Shao had many private correspondence, and after the battle of Guandu, a lot of bamboo slips of collaborating with the enemy were found in Yuan's camp. At this critical juncture, Guo Jia predicted: "Sun Ce has just annexed Jiangdong, and all he has killed are heroes, and he is a person who can make people serve death." But Sun Ce is a rash and unguarded person, although he has millions of people, it is no different from him coming to the Central Plains alone. If an Assassin were to ambush him, he would be a one-man enemy. In my opinion, Sun Ce must have died at the hands of the Assassins. Sun Ce arrived at the riverside, but before he crossed the river, he was killed by the enemy Xu Gong's disciples. This may be a coincidence, but it does add to Guo Jia's clever calculation.