This blog makes heavy utilization of tempo free statistics. The rationale behind using these ‘advanced’ stats (most involve simple arithmetic) was laid out beautifully by John Gasaway at Big Ten Wonk. Here’s a brief explanation of some of the key terms that you’ll find on this site:
Tracking the number of possessions in a game helps us compare the offensive and defensive production of teams that play at different speeds. We estimate the number of possessions in a game using the following formula:
Field Goals – Offensive Rebounds + Turnovers + (0.475 x Free Throw Attempts)
This formula is an estimate, but it is generally very accurate as its a sum of the plays that can end a possession.
Last year, the Division I average for pace was 66.4 possessions per game with a range of 59 to 76 possessions per 40 minutes.
Points per possession (PPP)
The number of points that a team scores per possession. This metric allows us to compare fast offenses to slow offenses and see which are more efficient.
Offensive and defensive efficiency are oftentimes used interchangeably with points per possession. These numbers are simply points per 100 possessions (PPP * 100).
The difference between offensive and defensive efficiency. Efficiency margin within conference play is a basic measure that can be used to highlight teams that might not be as good as their record indicates or that could be unlucky.
Effective field goal percentage (eFG%)
Like field goal percentage, but adjusted for the extra point awarded for three-point field goals.
The formula is:
(Field Goals Made + 0.5 * 3-Point Field Goals Made) / Field Goal Attempts
Effective field goal percentage should almost always replace field goal percentage, but 2-point and 3-point field goal percentages are often used to provide more in-depth analysis.
Turnover percentage (TO%)
The percentage of a team’s offensive possessions where it turns the ball over. Yet another simple calculation:
Turnovers / Possessions
Free throw rate (FTR or FTA/FGA)
A measure of how often a team gets to the free throw line. This is a simple calculation:
Free throw attempts / Field goal attempts
Offensive rebounding percentage (OR%)
The percentage of a team’s missed shots that it rebounds. Calculation:
Offensive Rebounds / (Offensive Rebounds + Opponent Defensive Rebounds)
The Four Factors
Together eFG% (shooting), turnover rate, offensive rebounding percentage and free throw rate make up the Four Factors to winning basketball games, as defined by Dean Oliver. Oliver’s estimated weights for the four factors is as follows:
- Shooting (40%)
- Turnovers (25%)
- Rebounding (20%)
- Free Throws (15%)