A list of tempo free terms and definitions used throughout the site. I have substantially borrowed from both Ken Pomeroy and John Gassaway’s sites in defining these terms.
First a little background. College teams play hoops at considerably different paces of play. They range from the legendary run and gun type offenses typified by the Loyola Marymount teams of the late 80’s (and exhibited today by VMI) to the disciplined passing and back door cuts of the Princeton offense (played in the Big Ten by Northwestern). Clearly, scoring 20 points per game for a Princeton style team means a lot more than 20 points for a Loyola Marymount squad.
The main distinction between these two styles is that teams will have a lot more possessions in a run and gun game than in a disciplined game. More possessions mean more opportunities to score, rebound, assist, turnover, etc. Tempo-free stats attempt to level the playing field by finding data that is independent of the pace a which a game is played. In many cases, that means expressing these stats in terms of a posssession.
For more detail, read this description from the Big Ten Wonk’s (John Gassaway) old site.
For the rest of the glossary, I’ll dispense with much of the philosophy and focus on the actual calculations behind the stats.
First the team based measures.
Possession – a possession ends when control of the basketball is gained by the opposing team. For statistical work, the real number of possessions in a game is approximated from the box score using the following formula: Possessions = FGAs – orebs + TOs + (0.475 x FTAs).
Game Pace (aka Tempo) – the average number of possessions in a game. It’s calculated by averaging the possession calculation for the two teams in the game.
Offensive Efficiency – the number of points that a team has scored per 100 possessions. Offensive Efficiency = 100 * (points scored / possessions)
Defensive Efficiency – the number of points that a team has given up per 100 possessions. Offensive Efficiency = 100 * (points given up / possessions)
Efficiency Margin – the difference between Offensive and Defensive Efficiencies.
Two Point FG% – in a standard box score you will see overall FG% and three point FG%. Overall FG% is a tempo free number but it means little. What’s important is is components – three point FG% which is usually published and two point FG% which is not. 2PT FG% = (Field goals made – three point field goals made)/(Field goal attempts – 3 point field goal attempts)
Two Point FG% – the opponents 2PT field goal percentatge. 2PT FG% Defense = (opponents field goals made – opponents three point field goals made)/(Opponent;s field goal attempts – opponents 3 point field goal attempts)
Three Point FG% – the standard calculation found in most box scores.
Three Point FG % Defense – 3PT FG % Defenese = the opponents 3PT FG%.
Free Throw Percentage – the normal number, it’s already a tempo-free stat.
Effective Field Goal Percentage – the first of Dean Oliver’s Four Factors, it takes into account 3 point shooting by giving extra credit for made threes. eFG pct. = (FGM + (0.5 x 3PM))/FGA.
Effective Field Goal Percentage Defense – your opponent’s effective field goal percentage. opponents effective FG pct. = (opponents FGM + (0.5 x opponents 3PM))/opponents FGA.
Offensive Rebounding Percentage – the second of the Four Factors, it’s the percentage of available rebounds of off your offensive glass that you nab. offensive RB%. = team offensive RBs/(offensive RBs + opponents defensive RBs).
Defensive Rebounding Percentage – the percentage of available rebounds off of your opponent’s glass that you take. defensive RB% pct. = defensive RBs/(defensive RBs + opponent offensive RBs).
Turnover Rate – the third of the Four Factors, the percentage of your possessions that result in a turnover. turnover rate – turnovers/possessions.
Turnover Rate Defense – the percentage of your opponents possessions that you turn into turnovers. turnover rate defense = opponents turnovers / possessions.
Free Throw Proficiency – the last of the Four factors, it measures your ability to get to the line and make your free throws. free throw proficiency = free throws made/field goal attempts.
Free Throw Defense – since your opponents actual free throw shooting is outside of your control this measures your ability to prevent them from getting to the line, which is under your control. free throw defensive = opponents free throw attempts/opponents field goal attempts.
Assist to Turnover Rate – a tempo free stat that was generally accepted as a key basketball measure before the concept of tempo based stats even got started. assists to turnover rate = assists / turnovers.
Assist to Turnover Rate Defense – your opponents assist to turnover rate. opponents assist to turnover rate = opponents assists / opponents turnovers.
Assisted Baskets – the percentage of made baskets that have been assisted. assisted baskets = assists / field goals made
Assisted Baskets Defense – the percentage of your opponents made baskets that have been assisted baskets defense = opponents assists / opponents field goals made.
Turnover Margin – the difference between your turnover rate and your opponents turnover rate. turnover margin = opponents turnover percentage – turnover percentage.