Being designed to collect as much information as possible about a game, the Possession Scoring Record System let us calculate probabilities of scoring for both teams over equal number of trials. Focusing on the player with the ball, following the ball from player to player until the ball is turned over to the opposition through a shot attempt or turnover.
Let us follow an example: team A with ball possession, can score, commit a turnover, or not get a rebound, the team B gets the ball. For each opportunity that team A get to score, team B also get a chance. This system sees by getting an offensive rebound, this keep alive its opportunity to score rather than producing another chance. Registering in this way, possessions are same number for both teams in a game. At the same time as each team has the same 40 / 48 minutes in a game to outpoint its opponent., each team has the same approximately 85 (in 40 minutes) / 100 (in 48 minutes) possessions in a game to outpoint its opponent.
In a non-overtime game, it is possible that each team will have as two more possessions than its opponents: see the reference to “1st. and last possession” at the eBA basketball Statistics Analysis System.
As was mentioned earlier, for this schools of thought on possessions, this formula is assuming that an offensive board "continues the possession", or "keeps the possession alive". On the second school of thought, including the eBA System, prefer to think of offensive rebounds and securing another possession. In which case total rebounds would be used instead of defensive in any possession formula.

A scoring possession is defined as a possession on which one or more points are scored. Then – and this is another topic – we define the ratio of scoring possessions to total possession as “floor percentage”. Another formulas ( see “Formulas eBA’ ) to study about this topic are:
Team Possessions = FGA - Oreb + TO + Up to Line Made (see the eBA System)
Team Scoring Possession = any possession on which the team scores at least 1 point
Individual Floor Percentage = the ratio of a player's scoring possessions to his total possessions
Individual Scoring Possessions = contribution to a team scoring possession through field goals, free throws, assists, and offensive rebounds.
Individual Possessions = sum of a player's scoring possessions, missed shots and free throws that are rebounded by the defense, and turnovers. ”.


This summary resumes this topic and will be completed at the "Formulas" chapter of the eBA basketball Statistics Analysis System. Another basketball rules topics you'll find at the basketball Stats Discussions section of our eBA Stats.com site.

Jorge Dunwhilli - ebastats - the basketball statistics forum