Recommend me a book for 11 year old boy

My little nephew is going through a tough time as his parents are going through a nasty divorce. They live in another country so he doesn’t even have his extended family close by to be there for him. His birthday is coming up so I want to send him some books which will inspire him, keep him hopeful about his future and maybe distract him from all the drama around him.

He is an advanced reader and mature for his age. He loves basketball, chess and is a math wiz. Looking forward to some suggestions.