Know the enemy, know yourself; your victory will never be endangered. Know the ground, know the weather; your victory will then be total.
Sun TzuUnless you know the mountains and the forests, the defiles and impasses, the lay of the marshes and swamps, you cannot maneuver with an armed force. Unless you use local guides, you cannot get the advantages of the land.
Sun TzuOne who has few must prepare against the enemy; one who has many makes the enemy prepare against him.
Sun Tzu