Some days later, when Xin Pi attended a feast hosted by Cao Cao, he noticed that Cao Cao had changed his mind after observing his facial expressions, so he spoke to Cao Cao's adviser Guo Jia. After Guo Jia told him, Cao Cao asked Xin Pi: "Can Yuan Tan be trusted? Can Yuan Shang be defeated?"(他日置酒，毗望太祖色，知有變，以語郭嘉。嘉白太祖，太祖謂毗曰：「譚可信？尚必可克不？」) Sanguozhi vol. 25. Xin Pi replied:
