Pitailu 否泰錄 is a text on Emperor Yingzong's (r. 1435-1449 and 1457-1464) disastrous campaign against the Mongolian leader Esen Khan (d. 1455, Chinese transcription Yexian 也先) in 1449. It was written by Lu Dingzhi 劉定之 (1409-1469), courtesy name Zhujing 主靜, style Daizhai 呆齋, from Yongxi 永新, Jiangxi. He also wrote an illustrated commentary on the "Book of Changes", Yijing tushi 易經圖釋. The title of the book is derived from two hexagrams of the Yijing 易經 and means approximately "disadvantageous non-combination".
The "northern hunting campaign" (beishou 北狩) of the ill-advised Yingzong found its end with the emperor being taken a hostage. His brother, Prince of Cheng 郕王, acting as resident regent, refused to answer to Esen's request to take him back. In 1450, Liu Dingzhi was appointed head of the Office of Transmission (tongzhengshi 通政使) and came, as Hanlin Academician (Hanlin xueshi 翰林學士), to the staff in the Hall of Literary Profundity (Wenyuange 文淵閣), which gave him access to documents, and also texts on the Mongols, like Yang Shan's 楊善 Fengshilu 奉使錄.