It's been a while since I read "Crossover: Fourth Quarter", but I'll do my best to answer your question based on my knowledge.
In the book, Jordan (JB) decides not to play in the championship game because he is dealing with some personal issues. His father has passed away, and he is struggling to come to terms with his grief. This makes it difficult for him to focus on basketball and perform at his best. Additionally, he is facing some conflicts with his family and friends, which further adds to his stress and distraction.
On the other hand, Josh decides to go ahead and play in the championship game because he feels it is important to honor his commitment to his team and to himself. He recognizes the importance of the game and the opportunity it presents to showcase his skills and potential. He also sees basketball as a way to cope with his own personal struggles, including the challenges he faces with his father's health.
Overall, the decision not to play or to play in the championship game is a personal one that is influenced by a variety of factors, including the individual's motivations, priorities, and circumstances.