Governing a large number as though governing a small number is a matter of division into groups. Battling a large number as though battling a small number is a matter of forms and calls.
Making the armies able to on opponents without being defeated is a matter of unorthodox and orthodox methods.
For the impact of armed forces to be like stones thrown on eggs is a matter of emptiness and fullness.
In battle, confrontation is done, directly, victory is gained by surprise.
Therefore those skilled at the unorthodox are infinite as heaven and earth, inexhaustible as the great rivers. When they come to an end, they begin again, like the days and months; they die and are reborn, like the four seasons.
There are only five notes in the musical scale, but their variations are so many that they cannot all be heard. There are only five basic colors, but their variations are so many that they cannot all be seen. There are only five basic flavors, but their variations are so many that they cannot all be tasted. There are only two kinds of charge in battle, the unorthodox surprise attack and the orthodox direct attack, but variations of the unorthodox and the orthodox are endless. The unorthodox and the orthodox give rise to each other, like a beginningless circle -- who could exhaust them?
When the speed of rushing water reached the point where it can move boulders, this is the force of momentum. When the speed of a hawk is such that it can strike and kill, this is precision. So it is with skillful warriors -- their force is swift, their precision is close. Their force is like drawing a catapult, their precision is like releasing the trigger.
Disorder arises from order, cowardice arises from courage, weakness arises from strength.
Order and disorder are a matter of organization, courage and cowardice are a matter of momentum, strength and weakness are a matter of formation.
Therefore those who skillfully move opponents make formations that opponents are sure to follow, give what opponents are sure to take. They move opponents with the prospect of gain, waiting for them in ambush.
Therefore good warriors seek effectiveness in battle from the force of momentum, not from individual people. Therefore they are able to choose people and let the force of momentum do its work.
Getting people to fight by letting the force of momentum work is like rolling logs and rocks. Logs and rocks are still when in a secure place, but roll on an incline; they remain stationary if square, they roll if round. Therefore, when people are skillfully led into battle, the momentum is like that of round rocks rolling down a high mountain -- this is force.