At that time, the number of Cao Cao's troops in Battle of Red Cliffs was never as high as 800,000, or even 200,000. Since the uprising of the Yellow Scarf Army in the late Eastern Han Dynasty, Beifang has been in a turbulent situation. First, Dong Zhuo was regent, and the vassal allied forces attacked it. Later, Cao Cao sold his family wealth, recruited soldiers and began to occupy the territory. Are going through wars, big and small. During this period, there were constant wars between Yuan Shao and Gongsun Zan, and Yuan Shao lost in the battle of Guandu. The infighting between the remnants led by Yuan Shao's two sons, together with Cao Cao, pacified them and resisted the invasion of northern ethnic minorities, and the losses were not small.

First, the national conditions of Wei at that time, after Cao Cao unified the north, the system of military and civilian reclamation was implemented. During this period, it is natural to build water conservancy projects and recruit refugees. Cao Cao did this for his own strength, of course, and these policies could effectively supplement the tense troops and food and grass at that time. But also can greatly reduce the number of refugees and prevent them from gathering to make trouble. Let the people have land to plant and food to eat, and let the people live and work in peace and contentment, and no longer suffer from exile. This has a positive effect on the stability of the country and is also beneficial to Cao Cao's rule. However, the battle of Guandu began in 199, and Battle of Red Cliffs was in 208. Cao Cao people don't have much time to recuperate. At that time, Cao Cao went south in Chibi, with a maximum of 103,400 soldiers and horses.

Second, the development of Sun Quan's regime in Jiangdong at that time was much more stable than that in the north from 197 to 2008. During the war, people in the north fled to the south to avoid chaos, bringing advanced farming techniques and a large population to the south. But when Battle of Red Cliffs happened, Sun Quan only gave Zhou Yu 30,000 military forces, plus Liu Bei and Liu Biao's eldest son Liu Qi's military forces were more than 50,000. Through this comparison, we can probably guess the number of soldiers and horses that Cao Cao could bring from the north at that time. Besides, when Cao Cao went south, Liu Biao's former subordinates would lead the people to surrender, and Cao Cao got Jingzhou Water Army. But at that time, Cao Cao actually only controlled two counties in the north-central part of Jingzhou, so Cao Cao did not get all the military power of Jingzhou. Jiangdong and Liu Biao have always been evenly matched. In fact, the number of military forces is only a little more than that of Liu Biao. Therefore, Cao Cao's military forces in Jingzhou are probably 50,000 to 60,000. Plus, the north only brings 200 thousand, which may not be enough.

800,000 is just a slogan that Cao Cao shouted when he went south, in order to strengthen his military strength and boost his morale. The actual number of soldiers and horses is probably only known to himself, because Cao Cao's enemies at that time were not only the south, but also the nomadic people in the west and north threatened him all the time. He couldn't help sending troops to defend, as well as his own base camp Xuchang and several important cities at that time. Also need to be heavily guarded. Therefore, only a part of the soldiers went south, but at that time, there were 300,000 soldiers and horses in Cao Cao's territory, and there was probably some. Moreover, the slogan is loud and clear, and exaggerating data is not only a unique symbol of the Three Kingdoms period, but also existed in various dynasties. In the face of this problem, we can only have different views, not all, and we must have our own calm judgment.