Records of Military Preparations, Volume 28

"One who is clear-sighted and wise can accurately weigh the strengths of both himself and his opponent. This allows him to determine in advance what can be sacrificed or abandoned. This level of strategic thinking is beyond Gongsun Yuan's reach. He will certainly attempt to block us at Liaodong first, and only later retreat to defend Xiangping The capital of the Liaodong region."

The Emperor asked: "How many days will the journey there and back take?"

Sima Yi replied: "One hundred days to travel there, one hundred days to conduct the siege, and one hundred days to return. If we allow sixty days for the troops to rest, the entire campaign can be completed in exactly one year."

In the sixth month, Sima Yi's army arrived in Liaodong. Gongsun Yuan dispatched his general Bei Yan and others to lead tens of thousands of infantry and cavalry. They took up positions at Liaosui and dug a perimeter of defensive trenches extending for more than twenty li: a traditional unit of distance, roughly 500 meters.

The various generals wished to attack them immediately. Sima Yi said: "This . is intended . to . exhaust . our . troops . indeed . To attack . them now . would be . falling . exactly . into . their . trap . Furthermore . the rebels' . main . force . is concentrated here in the north, which means their home base is empty and vulnerable. By heading straight for Xiangping, we will certainly destroy them."

Thereupon, he ordered many banners and flags to be displayed, acting as if he . intended . to emerge . from . the south .. Bei Yan . and the other generals . deployed . all . their elite . troops . to rush . toward that position .. Meanwhile, Sima Yi . secretly . crossed . the river . and emerged . from . the north ., heading . straight . for Xiangping.

Bei Yan and his men were terrified. They withdrew their forces and fled under the cover of night. The various units of the Wei army advanced to Mount Shou. Gongsun Yuan again sent Bei Yan...