If loss is inevitable, decrease yin to increase yang.

War, as a contest of strength, leads to losses on the part of the winner as well as the loser. The different lies in that the loss is inflicted upon the lose but is expected and accepted by the winner. It therefore follows that loss is always inevitable in war. By accepting this fact, a skilled commander formulates his battle plans so that the may gain a big victory at a small price. In the words of an ancient Chinese phrase, the decrease of yin (partial interest) can be made to benefit yang (overall interest). The idiom comes from a well-known Han Dynasty poem extolling brotherly love.