Long long ago, there was a general named Tianji who loved horse race very much. Once a time, he competed in horse race with Wei - the King of empire Qi. Both of them divided their horses into three levels. The horses that could run fastest were classified to level 1. The horses with normal speed were ranked to level 2. And the horses ran slower were grouped to level 3.
In the first match, Tianji chose one of his level 1 horses to contest against King Wei's level 1 horse. But his horse ran a little slowly and he lost the match. In the second match, Tianji chose one of his level 2 horses to play against King Wei's level 2 horse. But he got failure again. The same result came with the third match between the level 3 horses.
Tianji felt very disappointed and was going to leave racecourse. Then he saw his friend, Sunbin, who was famous for his wisdom. Sunbin came to front of Tianji and asked him "Do you wanna win the march?" "Of course", said Tianji, "but King Wei's horses are stronger a little than mine, I have no another faster horse." "Don't worry about it. With same horses, you can win the game too." Sunbin said confidently. Although Tianji was deeply surprised by what Sun had said, he chose to trust his friend.
Later, A new competition was hold between Tianji and King Wei. King Wei arrange his horse with the same sequence as before. But this time Tianji changed the order according to Sunbin's suggestion. He put level 3 horse at first, then put level 1 as second, and put level 2 at last. So the first match was Tianji's level 3 horse versus King Wei's level 1 horse. King Wei won match easily. In the second match, Tianji's level 1 horse versus King Wei's level 2 horse, Tianji won his first success. In the third match which was Tianji's level 2 horse versus King Wei's level 3 horse, Tianji won his success again. With two success of three matches, Tianji won the whole game.