This means that the party, especially the one who initiates a military engagement, should plan carefully in advance so as to avoid taking ill-prepared moves. A good commander expects to win victory by taking the initiative and will plan meticulously. On the basis of comparing his forces with the adversary in all aspects, the commander seeks to create the most favorable conditions for himself and make plans for all eventualities and changes to make sure that the engagement will unfold in the way he wishes and thus allow him to gain the upper hand. The saying that “do not fight if you are not sure of defeating the enemy” originates from this expression.

An army that always wins only engages in war when it is sure of winning, whereas an army that often suffers defeat engages in battle first and then hopes to win. (The Art of War)

In war, only engage when victory is assured. This means making careful evaluation of all aspects of the adversary’s army and commanders, and, on that basis, making meticulous plans for all possibilities to avoid mistakes or unpreparedness. (History as a Mirror)