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 →

One of the very first papers I ever published was “Trading Players in the National Basketball Association: For Better or Worse?”  Co-authored with Stacey Brook, it appeared in Sports Economics: Current Research (edited by John Fizel and Larry Hadley) in 1999.  Stacey and I wrote this paper early in our careers (I was a graduate student and he was a young professor) and looking back, one can tell.  As is often the case, graduate students and young professors (and of course undergraduates) are not the best researchers in economics and the social sciences (and we can frequently see evidence of this observation on-line).  This is because research isn’t just about playing with spreadsheets.  Like much in life, research requires experience.  And back in 1997 – when this paper was originally written (and yes, it often takes two years to get your work published) — Stacey and I were short on experience.

Today both Stacey and I have done a bit more. Between the two of us, we have more than 40 publications (and an excellent book).  So it’s possible that we could go back today and revisit the subject of our first publication in the field of sports economics.  Certainly I think, given our skill sets today, we could write a better paper.  Unfortunately, basketball has changed some since the 1990s and our visions of a better paper might be hard to realize.

In our paper we looked at the outcome of NBA trades.  The focus of these trades – again, back in the 1990s – was the specific players involved.  Today, though, often the focus appears to be less about players and more about cap space.  And with this new focus, it is increasingly difficult for researchers to evaluate whether or not a specific trade made sense.

The Billups Trade As It Was

To illustrate, consider the recent trade of Chauncey Billups for Allen Iverson.  As I noted when this trade was made, trading Billups for Iverson is not a good move for the Pistons.  Billups has consistently been more productive than Iverson.  To see how much “more productive”, let’s look at some numbers.

Last year the Pistons won 59 games with 60.6 Wins Produced.  As Table One notes, given the performance of its current roster last year, the Pistons should expect a Wins Produced of 49.6 when the 2008-09 season ends.  In sum, the team has lost about 11 wins from last year.  And almost the entire decline is due to the fact Billups is more productive than Iverson. 

Table One: The Detroit Pistons in 2008-09 after 54 games

This year Iverson and Billups have played 1,938 minutes for the Pistons (this is after 54 games, or after Sunday’s embarrassing loss to Cleveland).  In 2007-08, Chauncey Billups posted a 0.304 WP48.  Had Billups played those 1,938 minutes – and posted a 0.304 WP48 – he would have produced 12.3 wins after 54 games this season.  Across an 82 game season, this production would be worth 18.6 wins.

Now let’s look at Iverson. Last year Iverson posted a 0.134 WP48.  Across 1,938 minutes that level of production is worth 5.4 wins.  Or across 82 games, that’s 8.2 Wins Produced.  A bit of simple subtraction reveals the difference between Billups and Iverson – across the entire 2008-09 season — is 10.4 Wins Produced. In sum, virtually all of the difference between what the Pistons did last year and what the team should have expected this year is tied to the trade.

Of course the Pistons are not on pace to win 49 or 50 games this year.  After Sunday’s devastating loss to the Cavaliers, the Pistons have fallen back to the 0.500 mark (and after tonight’s loss to the Heat, the mark is now below 0.500).  And with a negative efficiency differential (offensive efficiency minus defensive efficiency) the team is actually on pace to win less than 41 games. 

If we look back at Table One we can assign responsibility for this outcome as well.  And again, part of the answer is Iverson.  As noted, Iverson posted a 0.134 WP48 last season.  This year he is only posting a 0.070 mark.  Consequently his expected Wins Produced is 3.7 off what we would expect given what he did last season. 

We should note that Pistons are also getting less from Richard Hamilton and Amir Johnson.  But fourteen of Detroit’s lost wins in 2008-09 can be tied to the Answer.  And that means Iverson is the indeed the primary reason the Pistons have slipped.

The Billups Trade As It Is Imagined

The team — and many observers of this team — has trouble with the Iverson answer.  The latest story – from Antonio McDyess – is that the Pistons are suffering from a lack of leadership. 

For a different take, we turn to Reggie Miller.  During the television broadcast of the Pistons loss to the San Antonio Spurs on Friday, Miller argued that Piston’s supporting cast (the cast supporting Iverson) is not good enough.  He even argued that Chauncey Billups has a better supporting cast in Denver.   Miller was not dissuaded from this argument even when Marv Albert noted that Denver lost Marcus Camby this past summer.  Consequently, it seems likely – as Albert noted — that the supporting cast Chauncey has in Denver in 2008-09 is less capable than the cast Iverson had in Denver in 2007-08.  Again, Albert’s observation failed to persuade Miller.

This leads us to wonder, how could Miller offer such a story? The problem Miller has – and other observers of the Pistons share – is that he “knows” Iverson is one of the all-time great players.  Given this belief, Miller has to find another explanation.  And even if that explanation makes little sense, it’s preferable to admitting that Iverson is not the answer.

The Billups Trade As It Can Be

One person who does seem to get the story of this trade “as it was” is Joe Dumars.  Thanks to Iverson’s expiring contract, the Pistons will be well below the NBA’s salary cap this summer.  Dumars was asked if he plans on spending this money in 2009, or if he is going to wait for the much anticipated free agent market in 2010. 

Dumars responded as follows:

“Given the fact we have to play a season next year, I think I need to use that money,” Dumars said of the expected $20 million or more the Pistons are expected to have available under the NBA salary cap.

“If we weren’t going to play next year I probably wouldn’t do anything with it, but I think we’re going to tip it off next year so I’m going to try and put a (good) team on the floor.”

Dumars said options will be plenty in the summer, and that could mean a trade or trades. He laughed when asked if he might wait for the much-ballyhooed free-agent class of 2010.

“You can’t wait,” he said. “You can’t sit here and two years down the road hope we get somebody. You have no idea what could happen. We’re not going to shut down. We’re going to keep going.”

Here is how I read this statement from Dumars: Continue reading →

About a week ago, Henry Abbott – at TrueHoop – posted The NBA Story No One’s Talking About About.  Essentially, the Sacramento Kings are losing money and it is possible this franchise – which has stopped in Rochester, Cincinnati, Kansas City, and Omaha – might be moving again. 

The problem for Sacramento – according to the team – is that the Kings are losing money.  Although it’s difficult to know how much (owners in sports are not always honest about their finances), one issue for the Kings is declining attendance.  Currently the team ranks last in the NBA at the gate.  

One reason for this decline could be the economy.  Today’s economic problems – which began in the housing sector – hit Sacramento and California especially hard.  But the economy is not the only problem for the Kings.  Let’s face it.  This team is bad.

The Bad Kings

To see how bad, let’s look at Table One.

Table One: The Sacramento Kings in 2008-09 after 57 games

An average player posts a WP48 [Wins Produced per 48 minutes] of 0.100.  As Table One note, only one player employed by the Kings this year has surpassed the mark of an average player.  That player – Brad Miller – is currently with the Chicago Bulls.  And the same story can be told about John Salmons, the second most productive player on the roster.  He is also in Chicago.

Of the remaining players, Kevin Martin is easily the best, although he is offering less than last year.  Even if he was as productive as last year, though, the Kings would still be a very bad team.

Once we move past Martin, this roster looks extremely bleak.  The rest of this team has only produced 0.2 wins this year.  Yes, Drew Gooden will help some when he is healthy.  But we should not be mistaken.  This team is built for the lottery. In other words, the choices the Kings made in building this roster have led to this outcome. 

More for Moore

Perhaps no player exemplifies this point more than Mikki Moore.  Continue reading →

Today is the trade deadline. So the obvious topic of choice is a discussion of a specific trade (or trades).  Unfortunately, most of the trades were really not that interesting (at least to me).  The one possible exception was the Jermaine O’Neal for Shawn Marion trade.  But in thinking about this transaction it occurred to me that I have already noted – as the following posts indicate– that Jermaine O’Neal is not quite as good as people think (a conclusion I think Toronto now understands). 

Sam Mitchell Learns that Bad Shopping can get you Fired

The Other Side of the Indiana-Toronto Trade

Did the Pacers Lose a Star?

The Most Overpaid in the NBA in 2007-08

Helping Bargnani

So in an effort to avoid repeating myself (too much), I am going to start the discussion by focusing on a Raptor who might benefit from O’Neal’s departure.  As the last post in this list indicates, O’Neal was the Most Overpaid Player in 2007-08.  The second player on that list is Andrea Bargnani.  And in thinking about the O’Neal-Marion trade, I found my thoughts turning to the idea that Bargnani is now going to be permanently thrust into Toronto’s starting line-up.

Bargnani has actually been starting for the Toronto since December 31.  But I think that’s because of injuries to O’Neal and Chris Bosh.  With O’Neal permanently out of the picture, Bargnani is now going to be the starting the center on this team.

Bargnani was the first player taken in the 2006 draft. And generally, when we think of the top choice in a draft, we think of a star.  At the minimum, we think of a starter.  But thus far Bargnani has only started 92 times in the first 199 NBA games he has played.  Relative to other number one selections — like Shaq, The Admiral, LeBron, Yao – it’s clear that Bargnani has not quite lived up to the standards of the number one pick.  But how bad has he been? Continue reading →

This past weekend – in the words of Henry Abbott – Michael Lewis (author of Moneyball) brought the Moneyball story to the NBA.  On the pages of New York Times Magazine, Lewis told the story of the No-Stats All-Star, Shane Battier.

As Lewis notes, “Here we have a basketball mystery: a player is widely regarded inside the N.B.A. as, at best, a replaceable cog in a machine driven by superstars. And yet every team he has ever played on has acquired some magical ability to win.”

Lewis contends that the traditional basketball metrics tell us that Battier is not an effective player.  Yet Battier’s teams tend to win.  To explain the magic that is Battier, Lewis turns to Daryl Morey (the young general manager of the Houston Rockets).  Morey argues that by looking past the box score – to a player’s plus-minus – the value of Battier can be measured.  And that measurement tells us Battier is a good player. 

In sum, the traditional box score in the NBA is simply inadequate if we wish to measure a player’s value.  Only the “advance” approach of plus-minus can tell us which players are “good” or “bad”.

Repeating the Story

The story Lewis tells is well-written and quite interesting.  It’s also not entirely original.

Here is what Matthew Yglesias observed on Monday:

Of interest to any fan of this blog will be Michael Lewis’ long New York Times Magazine article about Shane Battier, in which Battier becomes a jumping-off point for some discussion of analytic approaches to basketball. One thing about the article that bothered me probably had nothing to do with Lewis, but the piece has been given the headline “The No-Stats All-Star.” The implication being that statistics can’t measure Battier’s important contributions.

On the contrary, as Dave Berri observed in response to a similar claim back in November 2007 if you understand the statistics correctly they say Battier is very good. Stats say that Battier is an efficient scorer with his modest number of shots, and that his net possessions numbers resulting from steals and turnovers are very good. Battier also appears to be, as best as one can tell, an excellent on-the-ball perimeter defender. This last bit really is an aspect of the game that conventional statistics don’t do a good job of capturing, but certain statistical systems-including Wins Produced-indicate that Battier is a valuable player.

As Yglesias notes, the story told by Lewis has been told before.  The original author was Jason Freidman, who wrote Rocket Science: Daryl Morey Brings Hard-Core Statistical Analysis to the NBA in October of 2007.

When Friedman’s story appeared I posted the following:

What the Box Score Data Says About Shane Battier. 

This post built upon these two stories:

Walking in Memphis Back to the Playoffs (September 19, 2007)

Walking in Memphis (April 5, 2007)

Each of these columns detailed Battier’s contribution to the Memphis Grizzlies and Houston Rockets.  And those details – based solely on the NBA’s box score – revealed that Battier is indeed “good”.

The past few days a number of people have contacted me – via e-mail and the comments section in this forum – to comment on the Lewis story.  What I said back in 2007, though, is essentially what I would say today.  So my comment is going to consist of an updated version of my earlier post.  After this post, though, I will link to a few more stories on Battier and Plus-Minus (and also offer a few more thoughts). Continue reading →