11. The Nine Situations
The skillful tactician may be likened to the SHUAI-JAN. Now the SHUAI-JAN is a snake that is found in the Ch`ang mountains.
"Shuai-jan" means "suddenly" or "rapidly," and the snake in question was doubtless so called owing to the rapidity of its movements. Through this passage, the term in the Chinese has now come to be used in the sense of "military maneuvers."
Strike at its head, and you will be attacked by its tail; strike at its tail, and you will be attacked by its head; strike at its middle, and you will be attacked by head and tail both.