It’s a statistic to measure how “involved” a player is in an offense. As Ken describes it, “Percentage of possessions used (%Poss): A measure of personal possessions used while the player is on the court. Simply assigns credit or blame to a player when his actions end a possession, either by making a shot, missing a shot that isn’t rebounded by the offense, or committing a turnover.”
It’s basically the way to prove statistically if a guy is trying to do everything himself, or if he’s not overly involved in the offense.
Sam is 2nd on the team, behind Lundy, in this statistic.