What is Eff48?

Eff48 is a statistic that has been compiled by the NBA since 2002. It measures the sum of all of the player's positive production stats (points + rebounds + assists + blocks + steals) subtracts them from the sum of all of the player's negative production stats (field goals missed + free throws missed + turnovers), then divides that by the minutes the player played, and then multiplies that number by 48.

This statistic provides a much, much better... albeit still not perfect... measure of a player's performance than you would traditionally get just by looking at the player's points and rebounds. Unlike those stats, Eff48 rewards all-around production, while it penalizes "volume scorers" -- guys who score a lot of points but cost their teams by missing a lot of shots.

I also like it because it is comprehensive yet very easy to understand, unlike some other more mathematically inclined "performance" statistics (see Hollinger, John.. "Per" stats).

Here's how to read the Eff48 numbers:

Eff48 Easy Translator

40+: All-World

35+: All-Star

27+: Elite

23+: Pretty good

20+: Average

< 20: Below Average

< 15: Crappy

< 10: NBDL Reservations being made

What is PVOA

PVOA, or "point value over average" is a concept based upon the thinking behind footballoutsiders.com's DVOA, or "defense adjusted value over average". What it tries to capture is how a team performed based upon how the average NBA team would have performed given the same opponent and the same number of possessions.

Here's how its calculated. You take the opponent's established offensive and defensive efficiency numbers for the season (which are pts * poss/100 and pts allowed * poss/100, respectively), then you calculate the number of possessions in the game for each team (FGA + .44FTA + TOs - Offensive rebounds), and you multiply. Then you compare it against the actual number of points scored and points allowed for the team you are evaluating.

Example: Detroit plays the LA Clippers. Detroit won the game, 103 to 79. But I want to evaluate how Detroit performed against the average. So I look up LA's offensive and defensive efficiency numbers at this point in the season. They are 108.52 and 97.72. Then I calculate the number of possessions. That turns out to be 93.92 for Detroit and 91.32 for LA.

So, to evaluate Detroit's offensive performance I multiply their number of possessions 93.29 by the number of points LA has been giving up per possession, .9772. I come up with 91.78 -- that's what the average team has been scoring against LA in that number of possessions. But Detroit scored 103, so their "point value over average" is +11.22. Then you do the same for Detroit's defense, and it turns out they gave up 20.12 points less than the Clippers average number of points in that many possessions, so Detroit's defensive PVOA is -20.12, for an outstanding overall PVOA for Detroit of +31.34 (the defensive numbers, if negative, are considered positive when calculating Detroit's overall PVOA, and vice versa for offense).