to win a war with words
In the Warring States Period (战国), the State of Zhao (赵国) had a famous general called Zhao She, whose son, Zhao Kuo, was very fond of reading books on military science and discussingstrategy.
战国时，赵国名将赵奢 (shē) 的儿子赵括，喜欢看兵书，并且喜爱讨论军事战术。
He could learn military texts by heart, and when discussing warfare he spoke so clearly andlogically that it seemed that even his father was not his match.
When the State of Qin attacked the State of Zhao, the ruler of Zhao ordered Zhao Kuo to lead 400,000 men to resist the attack.
But since Zhao Kuo had no practical experience of battle, he was defeated and lost his life.
Later people used this idiom to describe those who are good only at theorizing, and lack practical experience.