Symbol: Mom's Text
Mom is texting Josh at the end of the novel when she is with Dad, and, at the end of her messages, the term "crossover" gets its own message. She's talking about Josh doing well on his crossover on the court, but the word sitting there all on its own is symbolic of Dad "crossing over" into death at the very same time as Josh is doing his crossover in the game.
Symbol: Josh's Hair
Josh's dreadlocks are extremely important to them; Samson-like, they symbolize his identity and his power. Thus, when they are gone, Josh feels as if his "wings" were gone. He begins to falter in life and makes a series of mistakes. Through losing his hair, he has symbolically lost who he is, and he must endeavor to find it again.
Symbol: Dad's Ring
Dad's championship ring fascinates Josh and JB, who see it as a symbol of their father's legacy and power. Dad got the ring in recognition of his prowess on the court, and it should be an honor when Josh gets it at the end of the novel. However, at that point in the story, Josh is not that pleased to inherit it on his own, thinking about how being "Da Man" did not save his Dad in the end. Symbolically, then, he tells JB they are both "Da Man" and the ring belongs to both of them; thus, Dad is represented by both of his sons, who can learn from his mistakes and represent different aspects of his personality.
Allegory: Basketball
The game of basketball is a fecund allegory for life itself, and Alexander makes reference to this numerous times in the text. In the game, as in life, a person makes mistakes and has successes. They have to work well with others, but they can have their moment to shine individually. They might trip, get hurt, or mess up, but what matters is that they get up and move on. There is a winner at the end, but winning is not as important as what one learns in this game of life: perseverance, teamwork, hard work, and self-worth.
Motif: Vocabulary
Throughout the text, Josh defines words and terms for the readers and for himself: churlish, pulchritudinous, myocardial infarction, calamity, and more. He is studying vocabulary in school, so these words are a nice reference to his education, but they are more important than that: these words also help Josh to make sense of his life and himself. Knowing the definition of something—churlish, for example—helps him to see how someone or something in his life corresponds to the word. For instance, Mom calls Josh churlish; when he looks it up, he realizes that he fits the description and that it behooves him to change. Thus, the words help Josh to navigate a world that often seems confusing or imprecise.