What is the overall meaning of Rowdy and Junior playing 1on 1 basketball at the reservation in The Absolutely True Diary of a Part-Time...

I think that the last scene is highly significant to the
manner in which Junior has constructed his identity.  The fact that Rowdy and Junior are
able to come back together as competitors that respect one another is significant.  On a
symbolic level, it shows that there will be a division, or compartmentalization, in
Junior's life between the identity he holds at Reardon and the notion of what he holds
in terms of life on the Reservation.  There is no subjugation of one over the other. 
The basketball court is Junior's soul or his canvass for identity and both forces,
Junior and Rowdy, compete and go back and forth in a game where there is "no score." 
This point is huge.  The fact that neither keeps score shows that there is a mutual
respect for one another.  The game is ongoing.  Yet, it also shows how the battle for
identity is ongoing.  There is no final point, no sense of totality in this vision .
Rather, Junior will go through periods where his "reservation" aspect is embraced and
moments where his "Reardon" identity is embraced.  Both vacillate between one another,
representing a pendulum that swings from side to side as identity is formed and the
notion of self is an ongoing element of consciousness and being in the
world.