He was severely punished for not knowing Pang Juan, and escaped bad luck after being skinned alive. At first, Sun Bin and Pang Juan were old classmates and close friends, and they were brothers. Later, Pang Juan heard that Wang Wei had published a list of talents, recruiting talents from all over the world with generous treatment.
Before he left, Pang Juan said to Sun Bin, "Don't worry, if I get Wang Wei's reuse and can make contributions, I will definitely recommend you to Wang Wei, and we two brothers will help Wang Wei and share prosperity.
"Later Guiguzi saw that Sun Bin was becoming more and more profound in the art of war, so he taught Sun Bin thirteen articles on the art of war that he had never taught. After learning what the teacher taught him, Sun Bin also went down the mountain to prepare for an exhibition. He remembered what Pang Juan said before he left and decided to defect. Seeing Sun Bin, Pang Juan was naturally enthusiastic on the surface, but secretly jealous in his heart. Worried that Sun Bin's arrival would replace his position in Wang Wei's heart, he changed his tricks to denigrate Wang Wei, saying that Sun Bin's ambition was not in Wei, but in Qi, and he could be above himself. He must not let Qi regard Sun Bin as a threat to Wei. Hearing this, Wang Wei made an excuse to punish Sun Bin and sent someone.