6.15

"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.