Battle of Guandu
During the Battle of Guandu, when his supplies were running out after a prolonged stalemate against Yuan Shao, Cao Cao sought advice from Jia Xu, who said: "My lord, you're wiser than (Yuan) Shao, braver than (Yuan) Shao, better at managing people than (Yuan) Shao, and more decisive than (Yuan) Shao. You have these four strengths, but the reason why you are unable to defeat him after six months is because you have been focusing too much on defence. You should be decisive when the opportunity arises, and victory will follow soon." Cao Cao replied, "Fine." He then led his forces to attack Yuan Shao's camps, which were spread out a distance of over 30 "li", and destroyed them. Cao Cao won a decisive victory over Yuan Shao at the Battle of Guandu and subsequently conquered the rest of Yuan's territories north of the Yellow River.