In the Romance of the Three Kingdoms, Chen Shou juxtaposed Xun You with Xun Yu and Jia Xu, and Guo Jia with Cheng Yu and others, and I think the most important reason was that Guo Jia died too early. Throughout the lives of Guo Jia and Xun You, the roles played by the two of them under Cao Cao were very similar, but unfortunately, Guo Jia died before the age of forty, and Xun You lived twenty years longer than Guo Jia and died at the age of fifty-eight.
Why is it that if Guo Jia did not die so early, there was a good chance that he would list a transmission with Xun You, because the two were really very similar. Xun You and Guo Jia, summed up in one sentence, are Cao Cao's brains in the frontline battles. In general, both of them are the kind of strategists who are decisive and decisive, and they are the kind of experts who make suggestions in specific battles.

At a very young age, Xun You showed an amazing ability to observe, and at the age of thirteen he could see people with adulterous faces.
In the thirteenth year of the year, he said to his uncle: "This official has extraordinary colors, and there will be adultery!" "The uncle asked, and the man killed and died.
Xun You's ability to detect such things at such a young age shows that his observation ability far exceeds that of ordinary people, and Xun You's observation ability has run through his whole life.
Guo Jia had a very good fight with Xun You in this regard. Before Guo Jia surrendered to Cao Cao, he had first met Yuan Shao, and after talking with Yuan Shao, through observation, he saw some of Yuan Shao's advantages and disadvantages, but Guo Jia's observation was very poisonous, because he said that Yuan Shao's words were zhujie, and there was almost no omission:
The wise man judges the Lord, so he can do everything in every way and his merit can be established. Yuan Gong's disciples wanted to emulate The Duke of Zhou, but they did not know the opportunity to use people. Many and widowed, indecisive, want to help the world in great difficulties, set the cause of the overlord, it is difficult!
Multi-faceted, indecisive, eight words, enough to include all of Yuan Shao's major shortcomings. This is Guo Jia's poisonous spicy. In terms of observation, Guo Jia and Xun You are so similar.
In the days when Cao Cao and Zhang Xiu were circling around Nanyang, Xun You had a representative work in terms of judgment, even exceeding Cao Cao's own judgment. At that time, Cao Cao wanted to take Zhang Xiu, Zhang Xiu was about to unite with Liu Biao, at this time, Xun You advised Cao Cao not to be too anxious, otherwise Liu Biao and Zhang Xiu would inevitably unite because they could not protect themselves, Xun You keenly captured the delicate balance between internal contradictions and external contradictions, but Cao Cao did not listen to Xun You at that time, and sure enough, Zhang Xiu and Liu Biao merged into one, almost surrounding Cao Cao's army, if it were not for Cao Cao's army digging tunnels overnight, transporting many heavy weights and troops out, and then setting up a qifu to defeat Zhang Xiu, Cao Cao's battle, and even possible to pay for his life.
Jian'an for three years, from Zheng Zhang embroidery. Yu Yu Taizu said: "Embroidery and Liu Biao are strong, but embroidery is eaten by the ranger on the table, and the table cannot be supplied, and it is bound to leave." It is better to wait for the army to wait, but it can be tempted; if it is urgent, it is bound to save each other. "Taizu did not follow, so he marched to Yong and fought. Embroidery urgent, the fruit of the rescue. The military is unfavorable. Taizu said, "You don't need to say yes." "It is a surprise soldier who returns to war and breaks it."
This is the characteristic of Xun You. In a concrete battle, he can have a clear understanding of the situation between the enemy and us and a realistic judgment of the current situation. If Cao Cao had taken Xun You's advice and not urgently attacked Zhang Xiu, then the internal contradictions between Liu Biao and Zhang Xiu would have overwhelmed the external contradictions between Liu Biao and Cao Cao and risen to the main contradiction, and at that time, Liu Biao would have been jealous of Zhang Xiu and would not send troops to aid him. On the contrary, if Cao Cao pressed too hard, Liu Biao and Zhang Xiu knew that if they separated, they would not be able to protect themselves, and they would inevitably unite against Cao Cao.
Guo Jia's first masterpiece in terms of temporary decision-making was when Cao Cao was recruiting Lü Bu. At that time, the Cao army itself had many troubles, on the one hand, the military food was not good, on the other hand, the Cao army came from Yanzhou, the labor army was far away, not only had several major battles with Lü Bu's army, but also besieged Lü Bu for a long time. Therefore, Cao Cao had already moved the idea of retreating, but Guo Jia immediately stood up to dissuade Cao Cao.
"Lü Bu has courage and strategy, and now the three wars are all north, and his sharpness is weakened." The three armies are dominated by generals, and if the main army declines, the army has no intention. Fu Chen Palace has wisdom and sees things late, and now and Bu Qi has not yet recovered, the palace plot is undecided, and the attack is urgent, and Bu Ke can also be pulled. ”
Guo Jia's characteristics are the same as Xun You's, and he is also able to keenly know himself and know the other in the midst of the imminent decision. On the one hand, Guo Jia knows very well that although our army is tired, the enemy army is also tired, and at this time, the loser is often not the weaker side, but the side that has not persevered to the end. Therefore, Guo Jia urged Cao Cao to persevere. At the same time, Guo Jia also keenly captured Lü Bu's think tank Chen Gong, a mastermind who had a strategy but was slow to see things, so even if Chen Gong had a plan, whether he could rush ahead of Cao Jun was a problem, and Lü Bu did not use it, it was another problem. Xun You did the opposite, and when Cao Cao's army was tired and even Cao Cao himself was ready to retreat, he instead asked Cao Cao to step up his offensive.
The Biography of Xun You says that Xun You:
Deeply secret and intellectual, since Taizu's conquest, he often plotted against him, and the people and disciples of the time did not know what he said. Taizu said: "Gongda is foolish and wise on the outside, courageous on the outside, weak on the outside and strong on the inside, not good, not labored, wise and reachable, foolish and unattainable, although Yanzi cannot pass." ”
Cao Cao's evaluation of Xun You can be said to be very comprehensive. Chen Shou's evaluation of Xun You was very high, saying that he:
Shu Hu has no exhaustive strategy, and after reaching the power change, its good and peaceful Ya Qi!
Directly comparing Xun You with Zhang Liang and Chen Ping at the same level. Moreover, even if there is no exhaustive strategy, this evaluation, in addition to Xun You, Chen Shou is only used on Jia Xu, Jia Xu He Xuren, the leading conspirator of the Three Kingdoms at the end of the Han Dynasty, on intelligence, no one is his opponent, the master of Mingzhe's self-preservation, and finally can live to be nearly eighty years old.
In the historical materials cited by Chen Shou, Guo Jia was evaluated as follows:
Guo Jiatong has a strategy and achieves things.
This evaluation may be slightly inferior to Xun You. But Chen Shou's evaluation is very comprehensive, he said Guo Jia:
Talent and strategy, the wonder of the world, although the Qingzhi virtue, different from Xun You, and the planning is expected, it is Qilun Ye.
Chen Shou said that Guo Jia was inferior to Xun You in terms of "Qing zhi de ye", but in terms of wisdom and strategy, he was of a level. What is Qingzhi Deye, like Zhuge Liang, there are eight hundred mulberry trees in the family and fifteen acres of thin fields. Therefore, Guo Jia and Xun You are very similar in all aspects, and the rare difference is only in the aspect of Qingzhi Deye.
References: Romance of the Three Kingdoms, Chen Shou, Zhonghua Bookstore, September 2006, 1st edition