The general who wins the battle makes many calculations in his temple before the battle is fought. The general who loses makes but few calculations beforehand.

do many calculations lead to victory, and few calculations to defeat

Battles are won by slaughter and maneuver. The greater the general, the more he contributes in maneuver, the less he demands in slaughter.

How do you decide a battle is lost? Numbers, strategic advantage, positioning? It's all worth a sparrow's fart. It comes down to men who are willing. The largest army will founder if its men are less willing to die than to win.

"17. Thus we may know that there are five essentials for victory: (1) He will win who knows when to fight and when not to fight. [Chang Yu says: If he can fight, he advances and takes the offensive; if he cannot fight, he retreats and remains on the defensive. He will invariably conquer who knows whether it is right to take the offensive or the defensive.] (2) He will win who knows how to handle both superior and inferior forces. [This is not merely the general’s ability to estimate numbers correctly, as Li Ch’uan and others make out. Chang Yu expounds the saying more satisfactorily: “By applying the art of war, it is possible with a lesser force to defeat a greater, and vice versa. The secret lies in an eye for locality, and in not letting the right moment slip. Thus Wu Tzu says: ‘With a superior force, make for easy ground; with an inferior one, make for difficult ground.’"] (3) He will win whose army is animated by the same spirit throughout all its ranks. (4) He will win who, prepared himself, waits to take the enemy unprepared. (5) He will win who has military capacity and is not interfered with by the sovereign. [Tu Yu quotes Wang Tzu as saying: “It is the sovereign’s function to give broad instructions, but to decide on battle it is the function of the general.” It is needless to dilate on the military disasters which have been caused by undue interference with operations in the field on the part of the home government. Napoleon undoubtedly owed much of his extraordinary success to the fact that he was not hampered by central authority.] 18. Hence the saying: If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat.

Generals usually know when a war is lost. The German generals had never been absolutely convinced that they could win World War II. They had only hoped to win it mainly because Hitler had promised them that the enemy armies would suffer amoral collapse and that they themselves would not have to fight a two-front war.

21. If he is secure at all points, be prepared for him. If he is in superior strength, evade him. 22. If your opponent is of choleric temper, seek to irritate him. Pretend to be weak, that he may grow arrogant. [Wang Tzu, quoted by Tu Yu, says that the good tactician plays with his adversary as a cat plays with a mouse, first feigning weakness and immobility, and then suddenly pouncing upon him.] 23. If he is taking his ease, give him no rest. [This is probably the meaning though Mei Yao-ch’en has the note: “while we are taking our ease, wait for the enemy to tire himself out.” The YU LAN has “Lure him on and tire him out.”] If his forces are united, separate them. [Less plausible is the interpretation favored by most of the commentators: “If sovereign and subject are in accord, put division between them.”] 24. Attack him where he is unprepared, appear where you are not expected. 25. These military devices, leading to victory, must not be divulged beforehand. 26. Now the general who wins a battle makes many calculations in his temple ere the battle is fought. [Chang Yu tells us that in ancient times it was customary for a temple to be set apart for the use of a general who was about to take the field, in order that he might there elaborate his plan of campaign.] The general who loses a battle makes but few calculations beforehand. Thus do many calculations lead to victory, and few calculations to defeat: how much more no calculation at all! It is by attention to this point that I can foresee who is likely to win or lose.

If a general and his men fear death and are apprehensive over possible defeat, then they will unavoidably suffer defeat and death. But if they make up their minds, from the general down to the last footsoldier, not to think of living but only of standing in one place and facing death together, then, though they may have no other thought than meeting death, they will instead hold on to life and gain victory.

A bold general may be lucky, but no general can be lucky unless he is bold. The general who allows himself to be bound and hampered by regulations is unlikely to win a battle.

(1) He will win who knows when to fight and when not to fight. (2) He will win who knows how to handle both superior and inferior forces. (3) He will win whose army is animated by the same spirit throughout all its ranks. (4) He will win who, prepared himself, waits to take the enemy unprepared. (5) He will win who has military capacity and is not interfered with by the sovereign. 18. Hence the saying: If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle.

Even if a king defeats his enemy in battle, that still doesn't settle anything. There are other, less numerous armies of philosophers and scientists, and their contests determine the true triumph or defeat of nations. One scholar is matched with another; one creative mind with another; and one judicious temperament with his counterpart. A victory won on that field counts for three won by force of arms.

He wins his battles by making no mistakes.
Making no mistakes is what establishes the certainty of victory, for it means conquering an enemy that is already defeated.

A soldier's life in combat is an endless series of decisions that mean success or failure, and perhaps life or death for himself or his comrades. The rifleman crawling through the rubble of a bombed-out street must decide on the best moment to escape enemy fire as he dodges from one doorway to the next. He must take a chance. The general seeking to break an enemy defense line and destroy his forces must decide just when and how to strike and precisely to what extent he dare weaken one sector of his front in order to mass overpowering strength at the main point of attack. He, too, must take a chance, although, in the stilted phraseology of military communiqués, he calls it a "calculated risk".

General becomes a Statesman, but he must not cease to be the General. He takes into view all the relations of the State on the one hand; on the other, he must know exactly what he can do with the means at his disposal.

As the diversity, and undefined limits, of all the circumstances bring a great number of factors into consideration in War, as the most of these factors can only be estimated according to probability, therefore, if the Chief of an Army does not bring to bear upon them a mind with an intuitive perception of the truth, a confusion of ideas and views must take place, in the midst of which the judgment will become bewildered. In this sense, Bonaparte was right when he said that many of the questions which come before a General for decision would make problems for a mathematical calculation not unworthy of the powers of Newton or Euler.