Know When to Fight

If you outnumber the enemy ten to one, surround them. Five to one, attack them. Two to one, divide them. If equally matched, you may engage. If slightly inferior, you can evade. If quite unequal, you must flee.

This is a mathematics of power that most people ignore. You do not fight every battle. You fight only the battles where the numbers are in your favor. If you are outnumbered, you withdraw — not out of cowardice, but out of intelligence. Find the ground where you are strong.

This passage is one of the most practical in The Art of War. Sun Tzu provides a clear decision matrix based on relative strength. The key insight is that withdrawal is not failure — it is a legitimate strategic option. The phrase 'if quite unequal, you must flee' uses the character bi, which means to avoid or evade, not to run in panic. It is a calculated decision to preserve strength for a more favorable engagement. Sun Tzu's ratios describe the conditions under which an army may surround, attack, divide, engage, evade, or withdraw. They are not a formula for judging a person's worth or a permission slip to dominate weaker parties. The underlying discipline is proportionality: do not mistake desire for capacity, and do not enter a contest whose likely cost you refuse to acknowledge. In civic or personal settings, choosing a different venue, asking for support, or leaving an unsafe confrontation may be wiser than trying to win on unfavorable ground. The ratios are a discipline against vanity. They also acknowledge that withdrawal can preserve a community for a later decision. In modern conflicts, the relevant form of withdrawal may be a pause, a mediator, a boundary, or an exit from danger—not an attempt to exploit someone with less power. Proportion protects judgment from pride, panic, and the pressure to perform strength.