Why advanced stats that center on possession based numbers? Because team’s play at different tempos and end up with a wide array of possessions played per game (per 40 minutes) on average. By using possessions played to calculate many of these numbers you can more effectively compare teams on an apples to apples basis.
eFG% (effective field goal percentage) accounts for the added value of the three point shot in to the player or team’s shooting percentage: ((0.5*3FGM) + FGM) / FGA
OReb% (offensive rebound percentage) percentage of available rebounds attained by the offense: Offensive Reb / (Offensive Reb + Opponent Defensive Reb)
DReb%, percentage of available rebounds grabbed by the defense: Defensive Reb / (Opp Offensive Reb + Defensive Reb)
Assist %, percentage of made field goals that came from an assist: Assists / FGM
Turnover %: Turnovers / Total Possessions
Steal %: Steals / Opponent Possessions
Block %: Blocks / 2FGA
The player stats shown here account for the number of personal possessions that the player spends on the court. That is figured by taking the player minutes divided by available team minutes and then applying that ratio to the total possessions played by the team in the game to estimate the number of possessions that player has personally logged.
Min % / Poss %: Minutes Played / (Team Minutes / 5)
OReb %: Player Off Reb / (Min % x (Team OReb + Opp DReb))
DReb %: Player Def Reb / (Min % x (Team DReb + Opp OReb))
Assist %: Player Assists / ((Min % x Team FGM) – Player FGM))
Turnover %: Turnovers / (Min % x Team Possessions)
Steal %: Steals / (Min % x Opp Possessions)
Block %: Blocks / (Min % x Opp 2FGA)