A player can resolve a possession in three ways. First, scoring himself, either a field goal (a two or three-point shot) or a free throw. Second, passing the ball, either because he effectively assisted one of his teammates or between his last pass and the situation who causes the end of possession (a basket, a foul or a dead ball) it touched two or more players. And third, losing possession, either because they have stolen the ball from his hands, or whether because, after a bad pass, the ball went out of bounds.

Well, following these criteria, we can divide the possessions in positive, neutral and negative ones.

We will call positive possessions to those where the player makes an assist. Neutrals, when the player passed the ball and they didn’t represent a goal pass. Negative, however, are those in which he causes "turnovers" given the reasons previously described. The ball possessions where the player scores, although for obvious reasons they are positive, are not taken into account for the ratio.

The reason for this calculation is to measure the responsibility of the point guard, as he spends most of the possessions of his own team. Often, the players who dish the most assists per game are those who have the most turnovers, since it is they who have the responsibility to "get" the ball in the half court offense.

For example. Magic Johnson holds the NBA all-time record for assists per game in a whole career, with 11.2.  However, nobody, in the period between his debut in the year 1979-80 and his first retirement due to AIDS at the end of the year 1990-91, have lost the ball more times than him. Jason Williams is another study case. Although his assist-per-game career average remained more or les estable throughout his entire career, his turnover indicators were sensibly affected, however, due to intra and extra sporting factors who forced him to maturate as a player. His explosive, sparky game shown in his second year in Sacramento (1999-00, where he averaged 7.3 assists with 3.65 turnovers per game; he led the total turnovers list in that year) to “only” 1.83 in his second year in Memphis (2004-05) and to lead the league’s assist-per-turnover ratio in that season, including a game with 15 assists… without losing the ball.

In forthcoming reports we will discuss about steals and its relation with turnovers.