When Dad ends up in the hospital, Josh angrily tells Mom that he's upset "because our backboard is splintered." In doing so, he draws a direct connection between the backboard on a basketball hoop--which keeps missed shots from going out of bounds and can be used to bounce the ball off of to make baskets--and to Dad, who performs a similar function in the Bell family. Like a backboard, Dad keeps Josh and JB in line and constantly points them in the direction of success.
The Backboard Quotes in The Crossover
Because the only thing that matters is swish.
Because our backboard is splintered.