Anyone familiar with the Romance of the Three Kingdoms knows that Zhang Gao and Gao Lan surrendered to Cao Cao because of the framing of Yuan Shao's adviser Guo Tu. The thirtieth time in the novel mentions that upon learning of the attack on Wuchao, Zhang Gao proposed that heavy troops should be sent to support Wuchao, but Guo Tu thought that Cao Cao's Guandu camp was empty at this time, and suggested that Yuan Shao launch an attack on Guandu. After Zhang Gao and Gao Lan failed to attack Guandu, Guo Tu, in order to evade responsibility, framed Zhang Guo and Gao Lan for having the intention of surrendering Cao, which made Yuan Shao furious and wanted to punish them. Zhang Gao and Gao Lan were horrified and eventually surrendered to Cao Cao.
But in fact, Zhang Gao was attacking Cao Cao's camp at that time, and when the news of Chun Yuqiong's defeat reached the front, Zhang Gao had already surrendered to Cao Cao, and he did not wait for Yuan Shao's defeat and Guo Tu slandered him, but he saw the action early in the morning, so Zhang Gao was not because of Guo Tu's slander and defected to Cao Cao.
The reason why Zhang Gao would turn against him before the battle was his careful consideration under the weighing of advantages and disadvantages. According to Zhang Gao's previous plan to Yuan Shao, once Wuchao was destroyed, Yuan Shao's army was gone, Cao Cao would be the victorious side, and Yuan Shao was mean and unkind, just for his own use, once defeated, he was afraid that he would be punished, plus Zhang Gao resented Yuan Shao for not believing him, and without his schemes, this would turn to Cao Cao's subordinates.
Guo Tu, the character Gongze, whose hometown was in Yingchuan, that is, in the area of present-day Xuchang Yuzhou, Henan, was a strategist under Yuan Shao at the end of the Eastern Han Dynasty, in the Battle of Guandu, he plotted to sneak into Cao Ying, but the plot did not succeed, Guo Tu in order to evade responsibility, blamed the blame on Zhang Guo and Gao Lan who led the army, resulting in the two defecting to Cao Cao, after Yuan Shao's death, Guo Tu served his eldest son Yuan Tan, and was eventually killed by Cao Cao.
Guo Tu became an official, thanks to a super Bole of the Eastern Han Dynasty: Yingchuan Taishou Yin xiu from Nanyang. And this Yin Xiu family is prominent, the ancestor is the famous Guan Zhong in the Spring and Autumn Period, Guan Zhong's seventh generation grandson Guan Xiu, migrated from the State of Qi to the State of Chu, was named Yin Dafu, and later took the "Yin" clan as a surname. In the Han Dynasty, the founding emperor of the Eastern Han Dynasty, Emperor Guangwu Liu Xiu, married the Yin Lihua of the Yin clan, leaving behind the classic famous sentence "Shi Eunuch is regarded as a Jinwu, and his wife should be Yin Lihua".
Guo Tu may not be as talented as Frustrated And Tian Feng, but he definitely has to win in figuring out the master's thoughts. Also as a strategist under the tent, Guo Tu knew more about Yuan Shao's heart, better understood Yuan Shao's "outer wide and internal taboo" characteristics, and was more keenly aware of the good great joy and self-sufficiency that had grown in his heart under the mighty situation of Yuan Shao's previous successive great victories. Instead of being depressed like Tian Feng and the two of them, foolishly insisting on their own opinions and contradicting the boss, it is better to push the boat down the slope and stand on the unified ideological front with the boss. Later, because Zhang Gao surrendered, which directly led to the victory of the Battle of Guandu, in order to cover up this fact, Guo Tu became a back cooker and was killed.