However, the Zizhi Tongjian account, which combined the Sanguozhi and Wei Shu accounts, did not mention the events on the first day – which were about Cao Cao sending all his available soldiers to defend the base and ordering women to stand guard on the walls. The incident is also mentioned in Sima Guang's Zizhi Tongjian. The 'ambush' mentioned in the Sanguozhi refers to the ambush that Lü Bu's forces fell into a trap on the second day, as described in the Wei Shu. Lü Bu's forces fell into the ambush and were defeated.

The next day, Lü Bu came to attack Cao Cao, and by then, Cao Cao had really set up an ambush near the dyke with the soldiers that had returned from gathering the grain. We must not fall into his ambush.' He then led his troops to 10 li(Chinese miles) south of Cao Cao's base and set up his camp there. Lü Bu suspected that there was an ambush, so he told his men, 'Cao Cao is very cunning. To the west of Cao Cao's base was a dyke, and to its south was a deep forest. When Lü Bu showed up, Cao Cao ordered all his available soldiers to defend the base and even ordered women to stand guard on the walls. Cao Cao had sent most of his troops out to collect grain so he had less than 1,000 men available in his base, which could not be well defended with so few men. The Wei Shu (魏書) gave a more detailed account of the ambush. At the time, Cao Cao had very few soldiers with him, but he set up an ambush and managed to defeat Lü Bu. In the summer of that year, Lü Bu went to Dongmin County (東緡縣 northeast of present-day Jinxiang County, Shandong) and gathered about 10,000 troops to attack Cao Cao. According to the Sanguozhi, in 195, the Empty Fort Strategy was used by the warlord Cao Cao against his rival Lü Bu in one incident at Chengshi County (乘氏縣 southwest of present-day Juye County, Shandong).

Zhuge liang strategies pdf