[6.13] Therefore, if we can make the enemy show his position while we are formless, the enemy is divided while we are at full force.
[6.14] If our army is at full force and the enemy is divided, then we will attack him at ten times his strength.
[6.15] Therefore, we are many and the enemy few. If we attack our many against his few, the enemy will be in dire straits.
[6.16] The place of battle must not be made known to the enemy. If it is not known, then the enemy must prepare to defend many places.
[6.17] If the enemy prepares to defend many places, then his forces will be few in number.
[6.18] Therefore, if the enemy prepares to defend the front, the back will be weak. If he prepares to defend the back, the front will be weak. If he prepares to defend the left, the right will be weak. If he prepares to defend the right, the left will be weak. If he prepares to defend everywhere, everywhere will be weak.
[6.19] The few are those preparing to defend against others; the many are those who make others prepare to defend against them.*
[6.20] Therefore, if one knows the place of battle and the day of battle,* he can march a thousand kilometers and do battle.
[6.21] If one does not know the place of battle and the day of battle, then his left cannot aid his right, his right cannot aid his left, his front cannot aid his back, and his back cannot aid his front.
[6.22] How much less so if he is separated by tens of kilometers, or even a few kilometers.
[6.23] Though Yueh's troops* were many, what advantage was this to them? You can achieve victory.
[6.24] Though the enemy is many, he can be prevented from doing battle. Therefore, know the enemy's plans and calculate his strengths and weaknesses.
6.19 the many are those who make others defend against them. Chinese commentator Mei Yaochen (1002-1060) explains this as the more defenses you cause your enemy to set up, the weaker your enemy will be (the fewer troops it will have in one place).