NBA Efficiency

Efficiency has long been measured by things like points per game and field goal percentage. However, these stats leave a lot of information out. For instance, if Ray Allen goes 2/5 from three, and Dwight Howard goes 3/5 on buttercups, haven’t they each scored 6 points in the same number of shots? What about a team that scores 100 points per game, but gets a lot of possessions in a run n’ gun style offense. That 100 points isn’t nearly as impressive, and this team’s opponents are getting an equal number of possessions each game (there’s a new rule in basketball that says possession alternates. Details.)

So here are a few stats to think about when measuring an NBA team’s efficiency:

Pace: Pace has to be taken into account when determining efficiency. Many of our most beloved stats are measure per game, yet teams play at various tempos. Most efficiency stats are adjusted to be per shot, or per possession.

Possession: One trip down the floor, which could result in any number of missed shots and put backs, a turnover, or a made basket.

Play: Like a possession, but each offensive rebound creates a new play.


Individual Stats

Usage Rate: An estimate of the percent of team plays a player “uses” himself. This stat can give us a measurable idea of the offensive load a player takes on. Kobe Bryant: 35.1%, Joel Przybilla 7.7%. See? So fun.

Total Rebounding Percentage (TRB%): The percent of total misses that end up in a player’s hands while he’s on the floor. The advantage over rebounds per game is that this statistic is now adjusted for the pace of play. Offensive RB% and defensive RB% are each measured separately, too.

Last season Dwight Howard grabbed 14.1 rebounds per game to Marcus Camby’s 10.3. However, the Magic averaged about 3 more possessions per game. That translated to 197 more missed field goals (offense and defense) in Magic games than Blazers games, and additionally Howard played more minutes. Thus Howard’s 21.8% rebounding percentage actually trailed Camby’s 24.1% in 2011. You could make a logical argument that Camby was a more efficient rebounder than Howard.

Assist to Turnover Rate: (A/TO): Just measuring a players assists doesn’t account for often the ball is in his hands. Likewise just measuring his turnovers leaves information out. Did he turn the ball over three times out of 30 possessions, or three times out of 9? By looking at the ratio of assists to turnovers, we see–on a simple level–how often a player did something good with the ball versus how often he did something bad with the ball.

Steve Nash may have led the world in total assists and assists per game, but he also turned the ball over a fair amount while trying to push the tempo. Jose Calderon finished the 2011 season with significantly fewer turnovers than did Nash, and Calderon’s 4.1 A/TO beat Nash’s 3.2 by a wide margin. Jose Calderon may not be as fun to watch, but his ball security makes him arguably a more efficient player, saving possessions for his team by not giving freebies to the opponent.

Assist and TO percentages (AST% and TO%): AST% estimates the percent of a team’s field goals assisted by a given player while on the court.  TO% attempts to measure turnovers per 100 plays “used.” Being ratios, both these stats better articulate the efficiency with which a player is handling the ball.

Steve Nash also paced the NBA in 2011 in AST% at 53%, indicating what our eyes tell us–that he’s probably the best playmaker around if you disregard turnovers. The Magic’s Chris Duhon led all guards with a 30.3 TO%, while The Thrilla Przybilla led everyone turning it over 34.1% of the time (among those with at least 500 minutes played).

Effective Field Goal Percentage (eFG%): Also known as points per shot (PPS), a ratio of points to shots taken. It does not include any consideration for free throws, but it’s a simple adjustment that doesn’t hurt three-point shooters like the classic FG% does.

True Shooting Percentage (tS%): Takes into account the relative benefits of both three pointers and free throws, and converts to something on the scale of FG%. Like a measure of individual points per possession.

Tyson Chandler finished third in FG%, but first in TS% due his ability to also make freethrows (73%). Despite the fact that posts dominated the top 20 in the conventional FG%, TS% helps to level the playing field for guys like James Jones (10th), Paul Pierce (11th) and Aron Afflalo (12th), and gives us a more fair way to compare scoring efficiency between different types of players.


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