Fighting with the river at his back
At the Battle of Jingxing, Han Xin faced two hundred thousand Zhao troops with thirty thousand raw recruits, drawing up his lines with a river at his back — a cardinal error by the art of war. The Zhao army sortied in full force, and the Han troops, with no way to retreat, fought to the death; two thousand light cavalry hidden in advance seized the empty Zhao camp and planted red Han banners everywhere. The Zhao troops looked back to see their camp changed, their formation collapsed, and they were routed in a single battle. Asked afterward how he had won against the art of war, Han Xin answered, "Cast them onto dead ground and they live — it is in the art of war; you gentlemen simply failed to notice."