Classic of Military Strategies, Volume 16

The army is divided into the Left and Right Wings, each led by a Military Commissioner Bingma Shi (兵馬使): a high-ranking officer responsible for the tactical movement of cavalry and infantry. The various ranks are arrayed in their proper order: formations are nested within formations, squads within squads, and companies within companies. Long-range weapons are balanced with short-range ones, and short-range with long-range. As the army wheels and turns, the rear becomes the front; they advance without rushing and retreat without panic.

Though they may appear confused and tumultuous, they remain organized and inseparable; though they seem chaotic and formless, their circular shape makes them impossible to defeat. This is the essence of the Orthodox and the Unorthodox Zheng and Qi (正奇): a core concept from Sun Tzu’s Art of War where the "Orthodox" (standard) force engages the enemy while the "Unorthodox" (creative or surprise) force secures victory.

One engages the enemy with the Orthodox and wins with the Unorthodox. The troops listen for the sound of instruments and watch for the signaling banners, suddenly merging together and suddenly breaking apart. To facilitate this, instructions are given repeatedly original: "三令五申" (sanling wushen), a classic idiom meaning to command strictly and repeatedly.:

• When the white flag is pointed and the drums roll, the Left and Right Wings merge together.
• When the vermilion flag is pointed and the horns sound, the Left and Right Wings separate.

In both separating and merging, the troops must not cross the Meridian Line original: "子午之地" (ziwu zhi di). This refers to the North-South axis of the battlefield, which served as a sacred or central boundary for maneuvering.. The Left Wing represents Yang and rotates toward the sun; the Right Wing represents Yin and rotates toward the moon. Eventually, each wing returns to its original position.

When the white flag is waved and the drums roll again, the troops disperse like rising clouds and scattering birds original: "雲蒸鳥散" (yunzheng niaosan), filling the valleys and spreading across the fields, yet they never lose their internal order or formation.