Points per Possession is THE most important stat in BASKETBALL
Here's how a team could have more possessions than their opponent at the end of the game:
In an NBA game, the team that wins the opening tip-off is awarded a throw-in pass to begin the fourth quarter, in addition to starting the 1st quarter with possession of the ball. The opposite team gets a throw in pass to start the 2nd and 3rd quarter.
If a team starts a quarter with possession of the ball and ends the quarter with possession...they will have one more possession than their opponent at the end of the quarter. Teams can start a quarter with possession in two of the four quarters. If the previously described scenario occurs twice, then a team will have two more possessions than their opponent.