Sun Tzu teaches that you must calculate the balance of forces before a battle. Strategy usually looks for ways to winning by avoiding opposition, but, when meeting an opponent is necessary, you can know if you will win or lose given meeting beforehand if you compare the five key elements that determine the strength of a position. You can thereby avoid battles that are certain losers.

In Sun Tzu's writing, the same Chinese character means both "ground" and "situation." Similarly, one character is translated as both "form" and "position." Sun Tzu's strategy teaches that it is the "form of the ground" or "your position in a situation" that determines your tactics: which methods work and which will fail. One of the most common mistakes in strategy is using methods that worked in one area in another area without understand the differences in the form or rules of the ground.