Years ago we took in NBA games with our eyes and through basic stats such as points, rebounds, assists, steals and blocks.
However, today we know that evaluating the NBA in such a manner will only tell you part of the story; advanced metrics are required to understand the game at its deepest levels.
Today we know that the player who scores the most points may not be helping his team win as much as the more efficient player who shoots a higher percentage from the field and helps his squad accrue more additional possessions.
The possession is the baseline of advanced stats. In order to win a game of basketball you need to use your possessions efficiently as well as regain possession of the ball through rebounding and forcing turnovers.
On a team level, offensive efficiency (the number of points a squad scores per 100 possessions) and defensive efficiency (the number of points it allows per 100 possessions) are the most telling measures of success.
On the player level, the advanced stats movement has yet to settle on a “Holy Grail” stat that can perfectly analyze everything that happens on a basketball court, but many useful measures have been produced.
Here’s a glossary of the advanced stats we chart in our Phoenix Suns player profiles:
PER (Player Efficiecy Rating) — A per-minute, pace-adjusted measure that returns a value for each of a player’s accomplishments (points, rebounds, turnovers, etc.). Essentially it’s a summary of everything a player does on the floor, as stat creator John Hollinger explains. The league average is set at 15.00.
TS% (True Shooting Percentage) — What a player’s shooting percentage would be if we accounted for free throws and 3-pointers. TS% = (Total points x 50) divided by [(FGA + (FTA x 0.44)] (Courtesy ESPN)
Usage — The number of possessions a player uses per 40 minutes. Usage Rate = { x 40 x League Pace} divided by (Minutes x Team Pace) (Courtesy ESPN)
Reb. Rate — The percentage of missed shots that a player rebounds. Rebound Rate = (100 x (Rebounds x Team Minutes)) divided by (Courtesy ESPN)
Ast. Ratio — The percentage of a player’s possessions that ends in an assist. Assist Ratio = (Assists x 100) divided by [(FGA + (FTA x 0.44) + Assists + Turnovers] (Courtesy ESPN)
Wins Produced — A measure that determines how many wins each individual player contributes to his team’s respective victory total, putting a premium on efficient scoring and possession acquisition. Its sophisticated formula is summarized on the Stumbling on Wins site.
WP48 — A ratio that determines the number of wins produced per 48 minutes. The average player will boast a WP48 of 0.100. (Courtesy Wages of Wins)
+/- — A comparison of how a team does when said player is on the floor and off the floor per 100 possessions. It can be summed up as (On Court Rating) – (Off Court Rating) = Overall Rating, with the ratings being measured on a per 100 possession basis. For more on the terms involved with +/-, consult Basketball Value.
Adj. +/- — Plus-Minus results adjusted to account for both the teammates and the opponents on the floor with a player during the period in question. (Basketball Value)
For further discussion of advanced stats, consult Kevin Pelton’s statistical analysis primer.