A possession is conventionally defined as a play that ends in either a turnover, a field goal, or a free-throw, with one exception: possessions are extended by offensive rebounds.
With this definition, we can aggregate field goals, free-throws, turnovers, and offensive rebounds to estimate a team's number of possessions. Note that possessions are unaffected by clock stoppages such as timeouts or non-shooting fouls.
The total number of free-throw attempts is multiplied by 0.44 to estimate possessions ended by free-throw attempts, controlling for one-shot instances such as technical fouls or and-ones.
Why is this useful? We can now use this estimation to calculate other advanced statistics, such as turnover percentage or offensive/defensive ratings.
Turnover Percentage
When looking at a team’s total number of turnovers in a game, we want to control for pace since more turnovers can sometimes be attributed to more possessions. Overtime games, a higher share of transition opportunities, or shorter possession lengths can all increase the pace of a game.
We calculate turnover percentage by simply dividing the total number of turnovers by total possessions, and TO% can be easily interpreted as the percentage of possessions that end in a turnover.
Offensive and Defensive Rating
We can also control for pace when it comes to points scored or allowed using Points Per Possession, or PPP. This stat is useful because it's straightforward and self-explanatory, but it can quickly lose interpretability with a few decimal places. Instead, we use Offensive Rating or Defensive Rating, which standardizes PPP or Opponent PPP over 100 possessions (roughly the average number of possessions per game in the NBA).
Lastly, we can calculate Net Rating (NRTG) by simply subtracting Defensive Rating (DRTG) from Offensive Rating (ORTG).
Where to Find TO%, ORTG, DRTG, NRTG
You can find these advanced statistics in most tables on the FastScout dashboard, as highlighted below.
Controlling for pace can be especially impactful against box scores, where averages can be misleading; a team may average more turnovers than their opponent, but they could also just be generating five more possessions per game. This is not to say that pace should be neglected since it can be a huge component of a team's identity, but by adjusting points and turnovers for pace, we eliminate the problem posed earlier by games with overtime periods, more transition opportunities, or shorter possession length.