Glossary

So, you’re wondering what all of these acronyms mean? You’ll find articles elsewhere on this site that might go into more detail on some of these stats, but it will hopefully be helpful, especially if you’re new to the site, to get a small dose of everything right away.

The following list is in alphabetical order by acronym. I’d suggest using your browser’s “find” feature if you’re looking for a particular item. Feel free to comment if I’ve left anything out, or if there’s anything you’d like me to explain further.

3FG – Three-point field goal

A made three point shot. Also “3PT.”

3FG% – Three-point percentage

The percentage of three-point field goals attempted that are made by the team or player. Formula: 3FG/3FGA.

3FGA – Three-point field goal attempt

An attempted three point shot, which includes both made and missed shots. Also “3PTA.”

“Adjust” or “A” prefix

When I use the prefix “A” or the word “Adjust” for a measure in my Excel sheets, it typically means that I have corrected an inherent bias in the numbers or otherwise changed the numbers to make them more accurate and/or meaningful. Adjustments may be for any reason, including (but not limited to) pace factor and schedule strength. Most commonly, I refer to AOff/ADef/ANet, which are schedule-adjsuted team efficiency numbers. I also use aOR/aDR/aNR for individual schedule-adjusted efficiency ratings.

A/AST – Assist

An assist is typically credited to a player whose pass immediately results in a teammate’s made field goal. The crediting of assists is somewhat subjective and may vary depending on the scorekeeper.

A/T – Assist to Turnover Ratio

The ratio of a player’s assists to turnovers, typically used as a measure of ball-handling or passing efficiency. Formula: A/TO.

aPER – Adjusted PER

More specifically, aPER refers to schedule-adjusted PER, based on my PLF (Player Leveling Factor) system.

AR – Assist Ratio

The assist ratio is a pace-adjusted measure that reflects the number of assists with which a player or team is credited per 100 possessions.

BI – Brick Index

The Brick Index is a Hollinger creation to show which players are hurting their teams the most by shooting poorly and shooting often. A number of factors are taken into consideration, and the formula is rather long, so I won’t list it here. A high positive brick index is not good.

BLK – Block

A block is credited to a defensive player who deflects an attempted shot, causing the shooting player to miss.

“D” prefix

The “D” prefix is typically used to identify the defensive counterpart of an offensive statistic.

DEff/DRtg – Defensive Efficiency/Rating

Defensive Efficiency is the conceptual twin of offensive efficiency (See “OEff” for more explanation), with lower numbers thus being more desirable. For teams, I use points allowed and Hollinger’s estimate for opponent possessions. For individuals, I use the scant defensive information available from box scores (defensive rebounds, blocks, and steals) to get a rough estimate for defensive efficiency. Even though it is based upon Dean Oliver’s formulas, this is not a particularly reliable estimate, so I tend not to use these numbers in individual player analysis.

DPoss – Defensive Possessions

Defensive Possessions are estimated for an individual based upon playing time, mainly because there are no better methods to estimate them using the traditional box score. More accurate methods do exist, but they are not prominently used because of the additional items needed from the box score.

DReb/DR – Defensive Rebound

A defensive rebound occurs when a missed shot is recovered by a player on the team that did not shoot the ball.

EC – Efficiency Contribution

A player’s overall contribution to his team’s efficiency, assuming that the rest of the team’s efficiency remains the same (which is probably not a valid assumption). The amount of the contribution is equal to the team’s efficiency with the player minus the team’s projected efficiency without the player. This is my own statistic, so it may or may not have merit, but it makes sense to me.

EC/%TP – Efficiency Contribution over Percent of Team Possessions

Individual Efficiency Contribution weighted for the player’s actual usage (%TP).

Eff – Efficiency

Efficiency can generally refer to a players offensive or defensive prowess from a statistical perspective. See “OEff” or “DEff” for more information.

FG – Field Goal

A made shot from any area of the floor.

FG% – Field Goal Percentage

The percentage of field goals attempted that are made by the team or player. Formula: FG/FGA.

FGA – Field Goal Attempt

An attempted shot from any area of the floor, which includes both made and missed shots.

Floor% – Floor Percentage

Floor Percentage is the percentage of a player or team’s total possessions that are also scoring possessions. Formula: ISP/ITP or ScPoss/TotPoss.

FT – Free Throw

A made free throw attempt.

FT% – Free Throw Percentage

The percentage of free throws attempted that are made by the team or player. Formula: FT/FTA.

FTA – Free Throw Attempt

An attempted free throw shot, which includes both made and missed shots.

Gm/Gms – Game/Games

The number of games played by an individual or team, and the basis for popular per-game measures like points per game and rebounds per game. These measures are typically not as meaningful as their corresponding per-40-minute measures.

GS – Game Score

Game Score is a back-of-the-envelope style calculation used to approximate a player’s PER on a single-game basis. It was invented by John Hollinger (as was PER), and it assigns a weight to each relevant event in the box score in order to give a single rating for a player’s performance within a game. Variants include GS/MIN (Game Score per minute).

IPP – Individual Points Produced

IPP is an estimate of the number of points actually produced by a player, taking into account the weight of other items that appear in the box score. Like Oliver’s other formulas, I won’t display it because of its complexity. This number is used to calculate an individual’s offensive rating.

ISP – Individual Scoring Possessions

As suggested by the name, ISP is an estimation of an individual’s scoring possessions based upon a host of factors, all of which are determined from the box score. Dean Oliver invented this statistic, and it is complicated enough to tie my spreadsheets in knots, so I won’t bother posting it here. You can read Basketball on Paper if you care to get the details. ISP is an intermediate statistic used to calculate Floor%, but it is useful on its own.

ITP – Individual Total Possessions

An elaboration of Oliver’s ISP formula, ITP is an estimate of the total number of possessions used by an individual. ITP is used as an intermediate step in finding Floor% and OEff, but it can be useful to see ITP on its own.

L – Loss

A loss is credited to a team that finishes a game with fewer points than its opponent.

MIN – Minutes

The number of minutes played by a player or an entire team. The typical NCAA game involves five or more players totaling 200 minutes for a maximum of 40 per player. This abbreviation may also refer to the number of minutes per game played by a specific player.

Net/NetRtg – Net Efficiency

Typically, I use the abbreviation “Net” as a reference to offensive efficiency minus defensive efficiency. This is perhaps the best metric for valuing the quality of a team statistically, but for individuals (because of the lack of precision of defensive efficiency numbers), it is not particularly useful. “Net” should not be confused with the object attached to the rim on the basketball goal.

OEff/ORtg – Offensive Efficiency/Rating

The concepts of offensive efficiency and offensive rating are one and the same, though I have probably referred to it using both names at times. In its most basic form, offensive efficiency is the number of points a team or player would score per 100 possessions. For individuals, I use Oliver’s estimates for points produced and possessions (ORtg=[IPP/ITP]*100), but for teams, I use actual points scored and Hollinger’s estimate for possessions (to stay consistent with the defensive efficiency calculation). See “IPP” and “ITP” for more information on the calculation of individual offensive efficiency.

OPoss – Opponent Possession

This is a crude abbreviation I use only to save space in Excel, and I probably haven’t used it elsewhere. See “Possession” for more info.

Opp prefix – Opponent

Any acronym with an “Opp” prefix is the opponent counterpart for a statistical measure. For example, OppTS% refers to a team’s opponents’ true shooting percentage. Put differently, OppTS% would be the true shooting percentage allowed by the team’s defense.

OReb/OR – Offensive Rebound

An offensive rebound occurs when a missed shot is recovered by a player on the team that shot the ball.

OR% – Offensive Rebound Percentage

The percentage of rebounds (from a team’s own missed shots) recovered by the shooting team. Calculated as (Team OR)/(Team OR + Opposing Team DR).

Pace – Pace Factor

The pace factor is a team rating that essentially is the number of offensive possessions for that team in an average game. This should not be confused with a team’s ideal pace, which could be lower or higher than the pace factor, depending on how other teams play them.

Pace-adjusted/Pace neutral

While it does not refer to a specific statistical measure, I use the terms “pace-adjusted” and “pace neutral” to describe measures that reflect the team’s pace factor by leveling the playing field in that respect. Some teams play at a faster pace than others, but metrics that are pace-adjusted neutralize that effect to give a clearer statistical picture. Many of the rate statistics posted here are pace-adjusted in some form, although certain ones (like per-40-minute stats) are not.

Pct. – Percentage

This abbreviation typically refers to winning percentage when used in the context of team standings. The formula is: W/(W+L).

PER – Player Efficiency Rating

The Player Efficiency Rating is John Hollinger’s attempt to quantify all of the good and bad contributions that a player makes into one statistical measure. Once these contributions are weighted, player production is then normalized to a league average of 15. I have made a number of adjustments to this formula in a continued attempt to reduce player production to one number, and the resulting adjustments have formed aPER, UPER, and SUPER.

PF – Personal Foul

A foul committed by a player. By NCAA rule, five personal fouls by one player in a single game result in that player’s ejection from the game.

Poss – Possession

A team possession occurs when the team controls the basketball and ends with a made basket, a defensive rebound, a turnover, or the end of a half or overtime period. For the purpose of statistical analysis, possessions can be estimated one of a number of ways. I typically use John Hollinger’s simple formula (FGA-OR+TO+[FTA*.44]) to estimate team possessions, even though it consistently overshoots the actual number by about 5%. I use Dean Oliver’s more intricate (and accurate) method for individual possessions.

PPR – Pure Point Rating

A formula used by John Hollinger to rate players on their perceived skill at running the point guard position in the traditional manner. The formula values a low number of turnovers, a high number of assists, and little else. Formula: ((A*2/3)-TO)*100/MIN.

PTS/TP – Points/Total Points

The number of points credited to a player or team. In virtually all scoring methods for organized play, a free throw is worth one point, a field goal from inside the 3-point line is worth 2 points, and a field goal from outside that line is worth three.

PtsProd – Points Produced

This number is used only in the team context, since it refers to the team total of its players’ Individual Points Produced (IPP), using the estimation formula provided in Dean Oliver’s Basketball on Paper. I will not attempt to display the formula here, since it is rather complex. I assure you that it is based on sound basketball and mathematical principles.

Pyth%/PW%/PW/PL – Pythagorean Win Percentage/Wins/Losses

The pythagorean numbers I use are based on the premise that a team’s record can be more accurately predicted by using net efficiency than by past wins and losses. This method uses the Pythagorean name because of Bill James’ adaptation for baseball, which is the following formula: PW%=(Runs Scored^2)/(Runs Scored^2+Runs Allowed^2), similar to the pythagorean theorem in geometry. Since basketball has a different scoring environment than baseball, the exponent I use is 9, rather than 2, but it serves the same purpose: predicting a team’s “real” record using net efficiency by removing the “luck” factors that previously influenced the team’s record.

Reb – Rebound

The recovery of a missed shot by a member of either team.

RR – Rebound Rate

Rebound Rate is an estimation of the percentage of available rebounds pulled down by a player, weighted based on playing time. Most players fall in the 5-15% range.

S/STL – Steal

A steal occurs when a defensive player intercepts a pass or otherwise takes the ball from a member of the team possessing the ball, resulting in a change of possession.

Schedule Adjustment/PLF (Player Leveling Factor)

This is sort of a blanket term for a system I introduced before the 2005-06 season. Basically, it’s my attempt to adjust certain statistics based on team strength of schedule. Team ratings vary from zero to 100 across all the levels of collegiate basketball, and the typical D-II team rates in the low-40s. Even though the schedule strength numbers vary widely, my adjustment is rather small. My introductory post on this system, where I explain how teams are rated, can be found here.

ScPoss – Scoring Possessions

This number is used only in the team context and is the total of the team’s players’ Individual Scoring Possessions (ISP). This is based on the estimation formula by Dean Oliver, which is too long to attempt to include here.

Stop

“Stop” is Dean Oliver’s term for a defensive event leading to a change of possession. Among traditional box score items, only defensive rebounds, steals, and blocks are used to estimate stops. More accurate methods exist, but they are not prominent because they use items not included in the traditional box score. This number is used to calculate an individual’s defensive rating.

Stop% – Stop Percentage

Stop Percentage is the percentage of a player or team’s defensive possessions that are “stopped” (see “stop”), using an estimate for defensive possessions based on playing time.

SUPER – Schedule-adjusted, Usage rate-weighted PER

This is the closest I’ve come to adjusting PER to make it accurately value player performance, at least based on what we know from the box score. That means it will be biased toward offense, but it’s still pretty good. SUPER does adjust for both schedule strength (using my Player Leveling Factor) and the inherent usage rate bias in PER. I chose SUPER instead of aUPER as the acronym for what should be obvious reasons.

TO – Turnover

A turnover is credited to a player or team that loses possession of the ball due to one of many different types of infractions.

TotPoss – Total Possessions

For the purpose of this acronym, Total Possessions are used only in the team context. TotPoss is the team total of its players’ Individual Total Possessions (ITP), based on the estimation formula by Dean Oliver. This number differs slightly from the “Poss” number that I use for team efficiency because of the differences between Oliver’s methods and those of John Hollinger.

%TP – Percent of Team Possessions

This is an individual measure used by Dean Oliver to show the percentage of a team’s total possessions used by a single player. It is not weighted based on playing time. While it is a variant of John Hollinger’s Usage Rate, the numbers will not correspond mathematically because the authors use different methods to estimate possessions.

TR – Turnover Ratio

Turnover ratio is a pace-adjusted measure that shows the number of turnovers a player or team commits per 100 possessions.

TS% – True Shooting Percentage

This simple metric was invented by John Hollinger to more accurately credit a player’s three-point and free-throw shooting (along with regular two-point field goal shooting) in one number. It is not an actual percentage, per se, so I typically will not use the % sign after it to avoid confusion. The formula is (PTS*50)/(FGA+[FTA*.44]).

UPER – Usage-Rate-Weighted PER

This adjustment to the PER formula accounts for a player’s usage rate in valuing overall production. Players with a high usage rate have an inherent advantage in accumulating positive production in the PER formula, so this adjustment levels the playing field somewhat.

UR – Usage Rate

A player’s usage rate is the percentage of team possessions used by that player when he/she is in the game. While this is a variant of the %TP formula, these numbers may not work out mathematically when calculating from one to the other because different authors use different estimation methods. John Hollinger uses Usage Rate, while Dean Oliver uses %TP.

W – Win

A win is credited when a team finishes a game with the more points than its opponent.

Further Reading

See the articles listed below for more information. If you’re really into this or you want to track the stats yourself, you should read Dean Oliver’s Basketball on Paper and/or one of the Pro Basketball Forecast editions by John Hollinger.

Outside sites:
Ken Pomeroy’s college basketball blog
APBRmetrics forum

My own articles:
Stats Primer
The Relative Effects of the Four Keys
The Four Keys Study Revised
A Player Rating Quandary
Revisiting Dean Oliver

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