There are five factors from which victory can be known: One who knows when he can fight, and when he cannot fight, will be victorious. One who recognizes how to employ large and small numbers will be victorious. One whose upper and lower ranks have the same desires will be victorious. One who, fully prepared, awaits the unprepared will be victorious. One whose general is capable and not interfered with by the ruler will be victorious. These are the five Way (Tao) to know victory.
Sun Tzu, The Art of War, c. 450 BCE