知己知彼，百战不殆
zhī jǐ zhī bǐ , bǎi zhàn bù dài

Translation

  • know yourself and know your enemy, and you will never be defeated (idiom, from Sunzi's "The Art of War" 孫子兵法|孙子兵法[Sun1 zi3 Bing1 fa3])
Chinese Tones