People tend to think economics is just about stocks, bonds, and money.  Certainly these are topics that many economists find interesting (I don’t know these economists, but I have heard stories). The broader subject of economics, though, is about resource allocation. From the perspective of this broader view we see economists look at such topics as the economics of happiness, crime, and marriage.  Of course such topics are important.  But not quite as important as the impact Stephon Marbury will have on the Boston Celtics efforts to repeat as NBA champions.

The Starbury Consensus

The consensus on this move appears to be as follows:

• Marbury is a very good player. In fact, Paul Pierce said his talent is “undeniable.”
• Marbury does not help a team’s “chemistry.” In other words, his lack of talent as a teammate is also difficult to deny.

Measuring “talent” and “chemistry” is quite difficult.  What we can do is think about this move in terms of resource allocation.

The primary resource players wish to consume is minutes and shots.  As is often noted, rewards in basketball (i.e. salaries, awards, etc…) are driven by scoring.  And players can’t score if they don’t get minutes and shot attempts. 

Although scoring leads to more money and attention for players, coaches are rewarded by wins. Therefore coaches should allocate minutes and shot attempts so that the chance of victory is maximized.

Resource Allocation at the Point

With this focus in mind, let’s look at what Marbury brings to the Celtics.  Starbury is a point guard, so therefore his minutes will come at the expense of Rajon Rondo and/or Eddie House.  Here is how these players compare with respect to WP48 [Wins Produced per 48 minutes]:

Rajon Rondo in 2008-09: 0.356

Eddie House in 2008-09: 0.157

Stephon Marbury in 2007-08: 0.036

Stephon Marbury in 2006-07: 0.070

Stephon Marbury Career: 0.105

Average WP48 is 0.100.   So Rondo amazing (in fact, he is the most productive Celtic), House is above average, and in recent years Marbury is below average.  Such numbers tell us that Boston is not helped by a re-allocation of minutes towards Starbury.  When we look at the individual statistics we can see why.

Table One: Comparing Rondo, House, and Marbury

The individual stats tell us why Rondo is so productive.  He excels with respect to shooting efficiency, rebounds, steals, and assists.  House is not quite as productive, but because he’s a very efficient scorer and avoids turnovers, House is also above average.

And then there is Starbury.  As I have noted in the past (see Starbury Loses His Star and The Wages of Wins is Factorial), Marbury might be “talented” but his productivity is not exceptional.  For his career he is below average with respect to rebounds, steals, and turnovers (the net possession factors). He is above average with respect to taking shots, but for his career he is a slightly inefficient scorer. 

In addition, when Marbury joins the Celtics he will be the oldest point guard on the roster. In other words, not only has Marbury done less than House and Rondo recently,  his age – and performance in recent seasons – suggests he’s getting worse. 

In sum, even if Marbury becomes a model citizen, re-allocating minutes to Marbury will not help the Celtics win more games.

The Bigger Picture

Marbury will take his minutes from Rondo and House.  But he can take shot attempts from the rest of the team.  And as we saw with minutes, such a re-allocation probably won’t help either. Continue reading →