LINKING OFFENSIVE AND DEFENSIVE EFFICIENCY TO WINS

 

Here is the model linking winning percentage to offensive and defensive efficiency

You can use this if you wish to figure out the expected wins for each team

(t-statistics in parenthesis beneath each independent variable)

Model estimated with data from 1991-92 to 2006-07

 

Winning Percentage    =       0.480 + 3.138 * Offensive Efficiency – 3.119 *Defensive Efficiency

                             (6.77)                   (63.8)                                      (-56.1)

Adjusted R2 = 0.94

 

Where

Offensive Efficiency = Points Scored divided by Possessions Employed (PE)

Defensive Efficiency = Points Surrendered divided by Possessions Acquired (PA)

 

Where

PE = FGA + 0.45*FTA + TO – REBO

PA = DFGM + 0.45*DFTM + REBD + DTO + REBTM

 

Where

FGA = Field Goal Attempts

FTA = Free Throw Attempts

TO = Turnovers 

REBO = Offensive Rebounds

DFGM = Opponent’s Field Goals Made

DFTM = Opponent’s Free Throws Made

REBD = Defensive Rebounds

DTO = Opponent’s Turnovers

REBTM = Team Rebounds

 

 

Readers of The Wages of Wins know we go from this basic model to the evaluation of each player’s Wins Produced (the steps – and there are four of them – are detailed in Chapter Six of the book).  And readers of the book also know that from Wins Produced we get Win Score.

 

It is also useful to review what is noted in the Technical Notes to the book:

 

Win Score and Wins Produced, the two models we use to evaluate NBA players, were both extensively detailed in the book (two chapters and eight pages of end notes are devoted to the construction of these two models).  Still, for those interested in even more details, the following papers will be of interest.

 

Berri, David J. (1999). “Who is Most Valuable? Measuring the Player’s Production of Wins in the National Basketball Association.”

Managerial and Decision Economics, 20, n8; Fall: 411-      427.

 

Berri, David J., and Anthony Krautmann. (2006). "Shirking on the Court: Testing for the Dis-Incentive Effects of Guaranteed Pay." 

Economic Inquiry. 44, n3; (July): 536-546.

 

Berri (1999) presents a model of wins that is not quite as good as the one presented in The Wages of Wins.  But the steps one follows to go from the estimation of the wins model to the measure of wins produced by a player are explained.

 

Berri and Krautmann (2006) presented the basic model of wins (based on offensive and defensive efficiency, which you can also see HERE) used in The Wages of Wins.  This paper also details a version of the metric labeled Win Score in the book.  The Berri and Krautmann (2006) work, though, does not incorporate blocked shots, personal fouls, and assists.  How those are added into the model is detailed in The Wages of Wins.

 

Or, you can turn to the following paper (to be published in 2008):

 

Berri, David J.   “A Simple Measure of Worker Productivity in the National Basketball Association.” In The Business of Sport, eds. Brad Humphreys and Dennis Howard, editors, 3 volumes, Westport, Conn.: Praeger. forthcoming in 2008.

 

This paper presents the entire Wins Produced and Win Score model.  If you read The Wages of Wins, as well as Berri (1999) and Berri and Krautmann (2006), you will not learn much that is new.  You will see an explanation of the link between team wins and offensive and defensive efficiency.  But once that link is established, readers of the book and the previous article will see much that is quite familiar.  Still, it might be good to see the entire story presented at once.