During the conflict between Han and Chu, after Han King Liu Bang captured the former Qin heartland of Guanzhong, he sent his great general Han Xin with an army across the Yellow River to punish Wei King Bao, who had betrayed Han for Chu. After Han Xin's victory, he pressed eastward to attack Zhao King Xie.
King Zhao and General Chen Yu led a large army to hold the strategic Jingxing Pass. Zhao's advisor Li Zuoju proposed, "The Jingxing passage is too narrow for two chariots to pass side by side. If Your Majesty grants me a force to take a small path and cut off the Han army's supplies, leaving them trapped with no retreat, within ten days they will surely be defeated."
Although this was an excellent strategy, King Zhao and Chen Yu refused to adopt it. When Han Xin heard the news, he was overjoyed and secretly admired Li Zuoju's strategic brilliance. He then ordered his troops not to harm Li Zuoju during the assault on the Zhao army, insisting that he be captured alive.
During the Battle of Jingxing, Han Xin deployed his troops with their backs to the river, a tactic that spurred his soldiers to fight with desperate courage, leading to a crushing defeat of the Zhao army. The King of Zhao was captured, Chen Yu was killed, and Li Zuoju was taken alive.
Han Xin personally untied Li Zuoche's bonds, treated him with great respect, and asked for his military advice. Li Zuoche initially hesitated, saying, "A general of a defeated army has nothing worth saying." Han Xin smiled and replied, "Please don't be modest. If the King of Zhao and Chen Yu had followed your strategy, I would be the one called a 'general of a defeated army,' not you."
Seeing how genuinely humble Han Xin was, Li Zuojia finally opened up and began to speak with him.
Later, the idiom "a defeated general" came to describe the losing side in battles and competitions.
Source: *Records of the Grand Historian*, "Biography of the Marquis of Huaiyin"
Meaning of the Idiom: Later, the Chinese idiom "败军之将" came to describe how the losing side in battles and competitions.