Possessions: How do we figure?

Back as promised, to discuss possessions or how we calculate them. First of all we need to clarify what a possession is. Probably the easiest way is to say what ends a possession. The incidents that expire possessions are listed following the jump.

1. A made field goal or free throw

2. A turnover

3. A missed shot (field goal attempt or free throw attempt) rebounded by the opposition

4. A tie up and going to the arrow the opposition gets the ball.

A key thing to note in all this is a shot attempt does not necessarily end the possession. If the ball is rebounded on the offensive end, the team in possession has, in fact, simply extended the possession.

Now we can chart every possession. That could be arduous and if we were not at the game, basically impossible. Instead we use a formula:

Possessions = FGA + (FTA * .475) - off. rebounds + Turnovers

Looks simply but what is this .475? Free throws can come at the end of a field goal with the shooter fouled, a one and one, two shot or even three shot foul. To arrive at a good estimate the attempts were figured by tempo free guru Dean Oliver to be best multiplied by .,475 to give us an accurate or as close as possible, number.

There have been times I have charted games and got the same possession total as the formula. There are other instances when the formula was off by 1-3 possessions. Not bad at all considering teams average anywhere from the low sixties to high seventies possessions per game.

Let us look at Vermont's performance against FDU on Wednesday. The 'Cats' numbers were:

FGA 56

FTA 18 (times .475 is 8.5 rounded up to 9)

OFF Reb 14

TO 17

Total possessions = 68

Vermont scored 71 points, giving points per possession (points divided by possessions) as 1.04

To get a nice 'workable' figure, multiply points per possession by 100 to obtain offensive efficiency, in this case 104 for the Catamounts.

The formula can be used to figure out efficiency of a half, four minutes or a season. You just need stats including points, FGA, FTA, turnovers and offensive rebounds. Oh, and a calculator.