"The army's positioning should imitate water. Just as water avoids the high and rushes to the low, the army's positioning must avoid the full and strike the empty. Just as water follows the ground, which determines its flow, the army responds to the enemy, who determines its victory. Therefore, the army does not have constant force, just as water does not have constant form."
- Sun Tzu

This is probably one of the most important passages in Sun Tzu, which describes how he envisions the army. For Sun Tzu, formlessness does not mean the army should have no positioning. Rather, it means that its positioning is completely dependent on the enemy - on the enemy's strengths and weaknesses. And thus, its positioning is always changing according to the enemy.

The army should never attack where the enemy is strong, but always aim for where the enemy is weak - where he is least prepared, where he is fewest, where he is not expecting. This is the driving principle for Sun Tzu's strategy.

As it should be for you, as well. Never go into a situation with a pre-determined strategy or plan. Your first step must always be to study the situation, understand your options, and choose the option that allows you to move forward with the least amount of resistance. 

"Therefore, his battle victories do not repeat, and his responding positions have no end."
- Sun Tzu

This passage harkens back to the previous Book on shih, where Sun Tzu tells us that it is through proper-surprising that one creates endless variations of achieving victory (5.4). For Sun Tzu, the winning combination of concealment and surprise allows one to continuously change one's position in response to the enemy's weak points. Because every enemy is different, one's strategy always changes. Yet the principles of attack - concealment and surprise - never change.

"Therefore, the ultimate military position goes as far as formlessness. If formless, then the deep gaps cannot be pried into, the wise cannot plan. Determine your position, and you let slip victory over the many. The many cannot be aware. All may know the position by which we achieve victory, but none may know the position by which we created victory."
- Sun Tzu

As he has stated many times before, victory in battle, for Sun Tzu, depends on one's ability to be concealed (or formless) until one can surprise the enemy at the points where he is weak. This is true especially if one's army is smaller than the enemy's. The element of surprise is crucial. If the enemy knows the position by which one strives to achieve victory, he can easily defend against it.

In your own life, concealment is equally as important. Conceal your intentions, conceal your strategy, conceal your positioning. People may be able to see that you achieved a certain position of success, but they should not be able to see all the little maneuvers you had to do to get there.

Everything rests on your ability to keep your situation hidden.

"Therefore, lure him, and you know his calculations for gains and losses. Feint him, and you know his logic for moving and stopping. Position against him [in battle], and you know his ground for dying and living. Compete with him [for resources], and you know where he has more than enough or is lacking."
- Sun Tzu

This passage details precisely what Sun Tzu means when he says to "know" the enemy (3.10). Knowing the enemy means understanding how the enemy will respond to various situations - that is, how the enemy thinks and what he values.

So, for example, luring the enemy tells you what the enemy is hoping to gain or avoid losing. Feinting the enemy - that is, pretending to attack one place - tells you how the enemy moves. Positioning your soldiers in battle shows you how the enemy will prepare to fight. Competing with the enemy for a certain ground tells you what the enemy needs.

Thus, for Sun Tzu, there are four key pieces of information the general must gather about his enemy's thought process:

1. How he calculates gains and losses
2. How he reacts to danger
3. What he is willing to fight to the death for (and subsequently, what he is willing to surrender or concede to)
4. What he is lacking or has in excess

All four of these key pieces of information allows one to do what Sun Tzu prescribes earlier in this Book. So understanding how the enemy calculates gains and losses allows one to "trouble him," "starve him," and "stir him" (6.2). Understanding how he reacts to danger allows one to "go out to where he does not hurry" and "hurry to places he does not expect" (6.3).

Understanding what he is willing to fight for or is willing to concede to allows one to control the time and place of battle (6.7). Understanding what the enemy is lacking or has in excess allows one to "rush to the enemy's weak points" (6.6).

As you can see, then, for Sun Tzu, having control over the battle relies on knowing the enemy - knowing how he thinks, how he makes decisions. In life, these same pieces of information are valid. Whenever you are competing you must determine:

1. How your competitors think about what would be a gain or loss
2. How they react to threats or changes in their environment
3. What they are willing to concede to and what they are willing to really compete for
4. What resources they already have and what resources they need

This becomes the basis of your strategy. To figure these things out, you'll have to employ the tactics Sun Tzu advises.

Lure your competitors with the prospect of some gain - for example, a rumor about you, a dissatisfied review, etc. - to see if they take the bait. Feint your opponents by threatening them in some area - for example, perhaps your business will take on a feature they offer - to see how they respond.

Take a stance on some area - for example, attacking them in public - to see if they take up the fight. Compete with them in some area - for example, for a certain client or market - to see how desperate they are for the resource.

Remember: the ultimate goal is to control the dynamic of the competition. If you have control over how your competitors respond, no matter how big or strong they are, then you have the advantage.

"By my estimation, though the soldiers of Yueh were many, what was their advantage in victory? Therefore, it is said: 'Victory can be achieved.' Thus, even if the enemy is many, he can be made not to fight."
- Sun Tzu

Here Sun Tzu provides a historical reference to the soldiers of Yueh to support his argument. Yueh was a southern state in Ancient China that was the enemy of Wu, the state Sun Tzu would come to serve. Despite Yueh's superior numbers over Wu, Wu would often win the battles.

Sun Tzu's point is simply to reinforce his points before - that absolute numbers do not matter. What matters is concentrating resources towards the enemy's weak points, i.e. where the enemy is not concentrated.

"If one knows neither the ground of battle nor the day of battle, then the left cannot assist the right, the right cannot assist the left, the front cannot assist the rear, the rear cannot assist the front. What is the situation if [one's enemy] is ten li away, or as close as one li?"
- Sun Tzu

For Sun Tzu, knowledge is the key to preparation. Without knowledge, one cannot coordinate a cohesive response. It is through attacking the enemy's knowledge - their ability to know where and when an attack is coming - that one is able to divide the enemy. A divided enemy allows one to concentrate one's forces at the enemy's weakest points, even if the enemy is numerous.

Take this to heart in your own life. Keep your intentions concealed. Don't let your competitors know when and where you are going to make a move. Your goal is to catch any competitor, especially if they have more resources than you, unprepared. As Sun Tzu tells us in Book 3, "One who, prepared, awaits the unprepared will win."

"Therefore, if you know the ground of battle and know the day of battle, then you can be a thousand li (away) and still join in battle."
- Sun Tzu

The foundation of success for Sun Tzu is knowledge. This is the pillar upon which everything else rests. As Sun Tzu tells us in Book 3, "[K]now the other and know the self, and in one hundred battles, there will be no danger." 

It is important to know, though, that what Sun Tzu means by "knowledge" is not how we normally think of knowledge. We tend to think of knowledge as "holding facts in our minds" - for example, knowing Abraham Lincoln is our 16th president or that two plus two equals four. We call this kind of knowledge "declarative knowledge."

What Sun Tzu means by knowing the ground and day of battle is different from this kind of knowledge. What Sun Tzu means by knowing the ground and time of battle is determining what is the most advantageous place and time for battle. Determining this is a matter of carefully analyzing the five factors mentioned in Book 1 (The Way, Heaven, Ground, General, and Methods).

Thus, the knowledge that Sun Tzu is speaking of is not simply the ability to articulate facts (i.e. what has happened), but to determine what the best course of action is and when the best time to take this course is, given one's current understanding of the situation. We can call this kind of knowledge "decisive knowledge."

For Sun Tzu, decisive knowledge gives one a sense of control (zhi), which is why he tells us that if you know the time and place of battle, "you can be a thousand li away and still join in battle." (A li is about a third of a mile, so over 300 miles away). This is because deciding, based on analysis, the place and day of battle allows you to march unhampered, take up a position that the enemy cannot attack, and attack where the enemy is unguarded (see 6.4).

In your own life, you need to develop your capacity for decisive knowledge. You need to look at your situation, analyze it, and determine when and where you are going to make your move. After knowing this, you can plan a route to effectively getting there.

It is important to note that decisive knowledge is not absolute. Your situation is constantly changing. In these situations (as we'll see in later Books), you'll need to hold your position and wait. But you always decide these decisions based analysis of the situation.

"The few is one who prepares his people. The many is one who causes others to prepare themselves."
- Sun Tzu

This is a very critical line that reveals the core of Sun Tzu's battle strategy. It both summarizes his thinking and defines the terms of use. For Sun Tzu, a relative size advantage is directly related to who has control over the dynamic of the battle.

The one who forced to "prepare" (bèi) is put on the defensive. They are few, as Sun Tzu explains, because their defenses must be thinned out. The one who forces others to prepare (i.e. through deception) has the advantage because they can concentrate their forces at the enemy's weak points.

 Thus, relative size is determined not by physical size, though it is measured that way. Rather, it is determined by psychology - by a person's decision-making to allocate resources at areas where they think they need protection. 

It doesn't matter whether overall one's army is bigger than the enemy's. What matters is that one's forces are concentrated with speed at the points where the enemy has the least number of resources - i.e. where he is least prepared. This starts by keeping the enemy on the defensive at every turn.

In life, the same is true. Stop focusing on how big or impressive or well-advantaged your competition is! Don't get distracted by that. Always try to focus on where your competitors are not concentrated. What areas are they forgetting about? Which clients are they ignoring? Which markets are they really underserving? Which relationships are they not cultivating? What internal needs are they neglecting or failing to address?

Then ask: of these areas, in which can I dominate? In which can I concentrate my forces with full speed?

As a result, because your competition does not have the resources, they will be "few." And because you are concentrated and ready to dominate, you'll be "many."

"Therefore, if he prepares his front, his rear will be few. If he prepares his rear, his front will be few. Thus, if he prepares his right, his left will be few. If he prepares his left, his right will be few. And if he doesn't have a place where he is not prepared, then there will be no place that will not be few."
- Sun Tzu

Here Sun Tzu is expounding on his logic in the previous verse, where he says, "If the places where the enemy must prepare is many, then the places where we join in battle will be few."

Sun Tzu's point in this passage is not simply that in preparing on one side, one becomes weak in another side. Rather, his point is that in having a clear position while one is formless makes it so that one has clear openings to attack while the enemy has only bad options. The enemy must constantly shift his defenses since he doesn't know where his opponent is going to attack. This shifting or anxiety - from not being able to see his opponent's positioning and from not having the control over the ground - is what allows for his opponent to take advantage and attack.

This is why, for Sun Tzu, it is critical that one occupy the ground of battle first and take up a formless position. This is what allows one to take control over the dynamic of the battle, to put the enemy on the defensive, and to, thus, thin out his defenses so that one can find the vulnerable points in his defense.

In life, the same principle obviously applies. What you are after is control over the dynamic of the competition. You want to get into a position where your competition is reacting to you without any ability to predict what you'll do next. This involves being prepared, taking the initiative, putting the competition on the defensive, and advancing at an angle that is unexpected yet powerful.

This takes a lot of calculation, but this is why you must always take a concealed position and never pitch a battle on ground that is already occupied. Always strive first to find niche where you can dominate.

"The ground where we join in battle must be unknowable [to the enemy]. If unknowable, then the places where the enemy must prepare will be many. If the places where the enemy must prepare is many, then the places where we join in battle will be few."
- Sun Tzu

This passage directly relates to the previous one. It is a fuller explanation of Sun Tzu's line where he says: "And if we, by means of our many, can strike his few, then the place by which we join in battle will be reduced."

For Sun Tzu, having a relative size advantage over the enemy is a matter of deception - blocking the enemy's knowledge of where and when to fight. This is why, for Sun Tzu, one must first occupy the ground of battle, and then do battle. One should never compete for already occupied ground.

If the place of battle is unknown to the enemy, then he will thin out his defenses preparing for an attack anywhere. Seeing this, a prepared general can select the few critical points at which he can send his soldiers to strike.

The point here works in your life as well: Your competitors should never know when or how you'll make a move. And where you should move should be where they are weakest or unprepared.