What do you mean by deliberately picking Jingzhou?

The loss of Jingzhou is the story of Guan Yu, a famous soldier in the Three Kingdoms period, who lost three counties in Jingzhou (Nanjun, Wuling and Lingling).

After Battle of Red Cliffs, seven counties in Jingzhou were divided by Liu Bei, Cao Cao and Sun Quan, and Liu Bei entered Sichuan, leaving five counties in Jingzhou occupied by Guan Yu (Nanjun, Changsha, Lingling, Guiyang and Wuling), among which Nanjun was borrowed from Wu Dong by Liu Bei. After Liu Bei got Shuchuan, he returned Changsha and Guiyang counties to Sun Quan (equivalent to returning Nanjun).

Later, Guan Yu sent troops to attack Cao Cao's Xiangfan area, and Sun Quan sent Lu Meng to attack the fall of three counties in Jingzhou (Nanjun, Wuling and Lingling), which led to the fall of three counties in Jingzhou. Careless loss of Jingzhou is now a metaphor for failure or loss caused by negligence, which means carelessness, pride and underestimation of the enemy.