Showing posts with label David Berri. Show all posts
Showing posts with label David Berri. Show all posts

Monday, October 15, 2007

Follow-up on "Wages of Wins" Review

In response to the New York Times' review of "Wages of Wins", the author, David Berri, posted some thoughts on his website:

Having reviewed some of the reaction to his story, though, I thought it would be useful to summarize what our research indicates about decision-making in the NBA. Here is a point-by-point summary of the story we are telling about the NBA.

Payroll does not explain much of wins in the NBA, MLB, or NFL. Specifically, payroll only explains 12% of the variation in wins in the NBA. In baseball explanatory power is 18% while in the NFL it is below 5%.

We think the low explanatory power of payroll in baseball and football can at least partially be explained by the relative inconsistency of performance in these sports. As we note in our book, across time in baseball and football we see fairly wide variations in player productivity. After all, who expected the Detroit Tigers to be so good this year?

Relative to these sports, though, performance in the NBA is more consistent. So why is payroll still unable to explain much of wins?

We think the answer lies in how players are evaluated in the NBA. For more than two decades economists have looked at the link between player salary and various performance statistics. Scoring totals are the only player statistic that consistently explains player pay. Shooting efficiency, rebounds, steals, and turnovers do not consistently offer much explanatory power. We updated these studies in our book. Our story, though, was essentially the same. Scoring totals are the one statistic that matters most in determining player pay.

How much players are paid is not the only decision economists have examined. Ha Hoang and Dan Rascher published a study in Industrial Relations in 1999. The Hoang and Rascher study looked at the factors that caused a player to be cut from an NBA roster. The only player statistic these researchers found to matter was scoring. All other player statistics did not matter.

We have looked at the coaches voting for the All-Rookie team and the factors that impact where a college player is drafted. What matters most? Again, scoring matters more than factors associated with getting possession of the ball (i.e. rebounds, turnovers, and steals).

Wins in the NBA, though, are not just about scoring. Possession factors have a large impact on the outcomes we observe in the NBA. When you look at all the statistics the NBA tracks you find that with these you can explain 95% of the variation in wins. And when you look at all these statistics you find that you can create a very accurate estimate of the wins each player produces.

From all this what do we conclude? Conventional wisdom in basketball is incorrect. Players who only score are not as valuable as people think. Players who do not score much — like Ben Wallace and Dennis Rodman – have a bigger impact on team wins than people seem to think.

Friday, October 5, 2007

Review on "Wages of Wins"

I was reading The New Yorker's review on "The Wages of Wins" by David Berri from May 29, 2006 earlier today. I have not read the book and was interested in reading Malcolm Gladwell's review. Two sections of the review stoodout to me:

The first:

In “The Wages of Wins” (Stanford; $29.95), the economists David J. Berri, Martin B. Schmidt, and Stacey L. Brook set out to solve the Iverson problem. Weighing the relative value of fouls, rebounds, shots taken, turnovers, and the like, they’ve created an algorithm that, they argue, comes closer than any previous statistical measure to capturing the true value of a basketball player. The algorithm yields what they call a Win Score, because it expresses a player’s worth as the number of wins that his contributions bring to his team. According to their analysis, Iverson’s finest season was in 2004-05, when he was worth ten wins, which made him the thirty-sixth-best player in the league. In the season in which he won the Most Valuable Player award, he was the ninety-first-best player in the league. In his worst season (2003-04), he was the two-hundred-and-twenty-seventh-best player in the league. On average, for his career, he has ranked a hundred and sixteenth. In some years, Iverson has not even been the best player on his own team. Looking at the findings that Berri, Schmidt, and Brook present is enough to make one wonder what exactly basketball experts—coaches, managers, sportswriters—know about basketball.

The second:

Most egregious is the story of a young guard for the Chicago Bulls named Ben Gordon. Last season, Gordon finished second in the Rookie of the Year voting and was named the league’s top “sixth man”—that is, the best non-starter—because he averaged an impressive 15.1 points per game in limited playing time. But Gordon rebounds less than he should, turns over the ball frequently, and makes such a low percentage of his shots that, of the N.B.A.’s top thirty-three scorers—that is, players who score at least one point for every two minutes on the floor—Gordon’s Win Score ranked him dead last.

At some point, I would like to read this book and dive further into Berri's calculations and thoughts.

http://www.newyorker.com/archive/2006/05/29/060529crbo_books1?currentPage=1