Author Archives: dberri

The best team in the NBA is…the Sixers???

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The following is from Dave Berri (who is now too lazy to post his own stuff — or just doesn’t want to do the tables the way Dre likes ‘em).

The NBA season is now two weeks old. Who is the best team in this very small sample?
To answer this question, let’s look at the team with the best efficiency differential — offensive efficiency minus defensive efficiency — in the NBA (we will define the “best team” as the team with the highest efficiency differential). Surprisingly, the “best” team after two weeks is the Philadelphia 76ers. After seven games, the Sixers have a differential of 16.1.

No team in NBA history has ever maintained a differential like this across an entire season.  And given the link between wins and efficiency differential — a link that explains 95% of the variation in wins — we would expect a team with a mark of 16.1 to win all their games.

This is not possible for the Sixers. They have already lost twice. Nevertheless, this team is playing quite well. And that leads us to wonder, what’s happening with this team.
If I wanted to answer this question in the past I would have to…

  • download the raw box score data
  • calculate each player’s ADJ P48
  • determine each player’s position on the team
  • calculate each player’s Wins Produced and WP48
  • create the tables and write the post

This entire process would obviously take quite a bit of time. And consequently – as Patrick Minton noted – it would take me awhile in the course of a season to touch upon each NBA team.

But thanks to Patrick, many of these steps have now been eliminated. To see this, let’s just go to The NBA Geek (Patrick’s website). On the top of the website you see a link to Teams. And once there, you can just click on the team you are interested in.  For this post, we are interested in the Philadelphia 76ers.

You can just click on the link above to see the details on the Sixers, but I guess I can do something. Here is just some of the information you would find at Patrick’s website:

2011-2012 76ers through 7 games
Player Pos G MP WP48 Points per 48 minutes WP WP for 66 games
Spencer Hawes C 7 212 0.376 19.9 1.66 15.7
Andre Iguodala SF 7 231 0.282 19.1 1.36 12.8
Jrue Holiday PG 7 241 0.157 20.7 0.79 7.4
Elton Brand PF 7 193 0.173 14.7 0.70 6.6
Nikola Vucevic PF 5 59 0.541 21.2 0.67 6.3
Louis Williams PG 7 182 0.174 31.6 0.66 6.2
Thaddeus Young PF 7 185 0.157 23.1 0.60 5.7
Evan Turner SG 7 185 0.153 17.9 0.59 5.6
Jodie Meeks SG 7 161 0.027 15.5 0.09 0.8
Lavoy Allen F 1 5 -0.030 0 0.00 0.0
Craig Brackins PF 4 11 -0.108 21.8 -0.02 -0.2
Tony Battie C 1 5 -0.239 0 -0.02 -0.2
Andres Nocioni SF 2 11 -0.125 8.7 -0.03 -0.3
Sum of
Wins Produced		 7.05
Forecast for
66 games		 66.5

Yes, I made that table. And it took me less than a minute (just did some copying). Okay, with table in hand, why are the Sixers “the best”? One might focus on Louis Williams.  He is the team’s leading scorer (per 48 minutes). Or Thaddeus Young or Jrue Holiday (two other leading scorers). These players are all above average (in terms of Wins Produced). But when we focus on Wins Produced, obviously the play of Spencer Hawes stands out.

Relative to an average center – yes, we can go to Patrick’s website and see that information as well (I am not going to make a table, just click on the link) — we see that Hawes is above average with respect to shooting efficiency from the field, rebounds, assists, turnovers, blocked shots, and personal fouls. Hawes is below average at the free throw line (both in terms of getting to the line and efficiency). But his positives add up to a level of production nearly four times beyond the average NBA center.

What is amazing about Hawes is what he did last year (and yes, we can go to Patrick’s website for this information). In 2010-11, Hawes was below average with respect to shooting efficiency from the field and the line. And he was not much better than average with respect to anything else. So he was a below average NBA player.

Given this past performance, we wonder if this can continue (as Devin wondered a few days ago when he commented on Hawes). But for now, Hawes is clearly driving what we see in Philadelphia.

That being said, there is more to the Sixers than Hawes. Of the players who have played more than 11 minutes, only Jodie Meeks is below average. Yes, the Sixers currently have eight players who are above average. Oddly enough, Meeks was above average last year (yes, Patrick reports the data on the 2010-11 Sixers). But Evan Turner and Louis Williams are now above average. And Andre Iguodala – who is once again more than twice the average player – is once again a star.

Just as we wondered with Hawes, we wonder if all this can continue. Can all these players stay above average? Well, we will see. It seems unlikely that this team could maintain a differential beyond 16 (again, this has never happened before).

Thanks to Patrick, we can check in every day and see how this team — and these players — continue to produce (or start to slip). And thanks to Patrick, if you aren’t interested in the Sixers (and are already tired — after two posts in a week — of hearing about Spencer Hawes) you can check in with any team you like. Patrick promises to keep updating his website. So rather than wait for me to get to your favorite team, you can now look every day at any team you like. It’s possible that the Sixers may very well stay the best team in the league.

- DJ

If everyone knew DeMarcus Cousins wasn’t a star, maybe he wouldn’t bother his coaches

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Dave Berri our esteemed General Manager decided to comment on DeMarcus Cousins’ recent actions. He was kind enough to post them over at the Huffington Post as well.

DeMarcus Cousins has demanded a trade from the Sacramento Kings. Or maybe he didn’t demand a trade. Certainly he has made his employers somewhat unhappy with his behavior, behavior that people argue goes back to high school.

Before I offer some thoughts on Cousins’ behavior, let me note that his behavior reminds me of the actions of another group of people I come into contact with on a regular basis.

Of course, I refer to academics. No, most academics don’t often wow a person with their physical skills (although you can be wowed by their lack of physical grace). Academics, though, can exhibit the same attitude issues. To be fair, I am not talking about all academics. But certainly some people in the academy can exhibit attitudes. And this comes about for the same reason athletes exhibit this kind of behavior. When you are the best in your group (i.e. star player on the team, smartest kid in class), you tend to act… well, like you’re the best in your group.

In general, when I come across a fellow academic who is very accomplished, I tend to be okay with the attitude that can come with these accomplishments. What can be annoying — at least to me — are people whose attitudes are not aligned with their level of accomplishments. Yes, some academics can have attitudes without actually doing much (i.e. they have not published much, are not great teachers, etc…). And that can be a problem. At least, such behavior in other people bothers me (if I did something like this… well, I wouldn’t be as bothered).

The lack of alignment between attitude and accomplishment reminds me very much of the Cousins case. It seems clear that Cousins thinks he is a star. And perhaps he has some reason to reach this conclusion. After all…

And this season — after just five games — Cousins is averaging 11.2 points per game and leads the Kings with 10.6 rebounds per game (see Basketball-Reference.com for all of these box score numbers). These numbers suggest Cousins is a star.
But if we delve deeper into the numbers it becomes very clear: Cousins ain’t a star in the NBA.

To see this point, let’s look at some more numbers.

DeMarcus Cousins vs. an Average NBA Power Forward
Below average numbers in red
2011-12 numbers as of January 4, 2012
Statistics Average Power Forward 2010-11 2011-12
Points 19.5 23.8 20.5
Adjusted Field Goal Percentage 49.0% 43.2% 31.0%
Free Throw Percentage 72.3% 68.7% 74.1%
Field Goal Attempts 15.9 20.9 21.3
Free Throw Attempts 5.4 8.4 9.9
Offensive Rebounds 3.5 4.5 10.6
Defensive Rebounds 7.7 10.0 8.8
Steals 1.4 1.8 2.2
Turnovers 2.7 5.6 4.8
Assists 2.8 4.2 1.8
Blocked Shots 1.3 1.4 2.6
Personal Fouls 4.9 6.9 8.1
Wins Produced per 48  minutes 0.100 -0.064 0.018

The table above indicates that Cousins is above average — for an NBA power forward — on the boards. He is also good at getting steals and blocked shots. And during his rookie season, he could get assists. All of this is good.

But the numbers in red are where Cousins has problems. We can start with the issue of turnovers. Cousins — relative to an average player at his position — is almost twice as likely in his career to turn the ball over. So Cousins clearly has a problem hanging on to the ball.

When he does hang on to the ball, though, we see a much bigger problem. Cousins is well below average with respect to shooting efficiency. Simply put, Cousins can’t shoot very well. This is a very big problem because Cousins is very fond of shooting the ball. As a rookie he led the Kings in shot attempts from the field. And this season, no player on the Kings who has logged at least 50 minutes takes more field goal attempts per minute than Cousins.

This would be fine if Cousins was an efficient scorer. But only three players on the Kings in 2010-11 were less effective scorers (in terms of adjusted field goal percentage). And all three of these players didn’t shoot much last season (relative to Cousins) and all three are not employed in the NBA this season.

This season Cousins is very much employed (despite the attitude problems) and has gotten much worse. No player in the NBA who has taken 50 shots from the field this season is shooting worse than Cousins.

To see how much worse, let’s talk about wins. All of the above numbers are used to calculate the number of wins Cousins has produced as an NBA player. When we take that step, we see that Cousins’ negatives overwhelm his positives. In 2010-11 — when most coaches thought Cousins was one of the best rookies — Cousins only produced -3.1 wins (yes, that is a negative number). Only one player in the NBA was less productive last season. So Cousins was not really one of the best rookies in 2010-11.

This season Cousins is better. Well, at least he is no longer in the negative range. But with only 0.05 Wins Produced this season, he is still well below average. Yes, he has improved dramatically with respect to rebounding. But because Cousins likes to shoot and so far can’t shoot — he is simply not a productive NBA player. In sum, he is not a star.

One should note, that Cousins probably likes to shoot because the NBA rewards this behavior. Studies have shown the coaches’ voting for the All-Rookie team is primarily determined by points scored. Points scored also historically get a player paid. So Cousins — despite being a poor shooter — has an incentive to take as many shots as he can. More shots lead to more points, and more points cause people to think a player is a “star.”

But when we look past scoring totals and focus on efficiency, it’s very clear that Cousins is not a very good NBA player. And if this was understood by Cousins and the Kings coaching staff, one suspect Cousins would behave very differently.

To see this point, let’s talk briefly about baseball. Can one imagine a baseball player who was one of the least productive players in the game demanding a trade? Or causing his coaches problems day after day? Such behavior from poor players is discouraged because

  1. Performance in baseball is well understood
  2. Bad performance can easily get you sent off the roster (i.e. to the minors)

In basketball, though, performance is too often evaluated in terms of totals, and not in terms of efficiency. Consequently, players know that the more they shoot — even if they don’t shoot very well — the better they will be seen. Cousins seems to be taking advantage of this issue with respect to player evaluation in the NBA. And as a result, it is hard for his coaches to discourage his bad behavior. The coaches think Cousins is a “star,” and therefore they are reluctant to simply sit Cousins until he learns how to

  1. Shoot the ball efficiently
  2. Stop turning the ball over
  3. Behave himself

Let me close by noting that if Cousins did (1) and (2), then he probably wouldn’t have to do (3). Again, people tend to be somewhat tolerant when a “star” has an attitude. What shouldn’t be tolerated is people who are clearly not good at what they do acting like they really are a “star.” At least, I have a hard time tolerating such behavior (again, in other people).

-DJ

Checking in on a Prediction

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Economists aren’t known for getting predictions right.  Nevertheless, we keep trying. 

My latest prediction – which was revealed in an article by Ron Dicker at Huffington Post – was that television ratings for NBA games this Christmas would exceed the ratings seen for games played on Christmas last year.  This prediction — made a few weeks ago — was motivated by the research I published with Martin Schmidt on the impact labor disputes have on attendance.  As we noted in The Wages of Wins, fans may say during a labor dispute that they will hold a grudge, but the data makes it clear that this is an empty threat.  Although this research was about attendance, I predicted we would see a similar story with respect to TV ratings.  And as I revealed today in my latest at Freakonomics…. well, go read the post. 

I will add this bit of information.  In the 33 days since the NBA lockout ended, we have had more than 90,000 page views at the Wages of Wins Journal (according to WordPress).  From November 26 to December 28 of 2010 (or last year at this time), this blog only had about 53,000 page views.  This is somewhat surprising, since NBA games were actually being played for this entire time period in 2010.  But one suspects that fans became very interested in the NBA once the lockout ended. 

Then again… last year the primary writer in this forum was me.  And this year, other people are doing almost all the writing. So maybe this all simply reflects a change in the talent level in this forum :)

- DJ

Is Dallas better than last year?

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Thanks to the shortened free agency period inflicted by the lockout we are being overwhelmed by NBA news. Many franchises are in a mad dash to make their teams worse (we’ll post on that, don’t worry!) but a surprise story is that the defending champions may have in fact secretly improved themselves in several ways.

Here’s a brief rundown of the Mavericks offseason thus far (2011 Numbers can be found here):

Last season Tyson Chandler was very good. The New York Knicks clearly noticed and offered him a contract worth roughly $15 million a year. The Los Angeles Clippers did not get the memo that Caron Butler has been steadily declining and offered him a contract worth roughly $8 million a year. The Los Angeles Lakers managed to fleece Lamar Odom into a terrible contract. He will make roughly $8.5 million over his next two seasons. Additionally only this season is guaranteed.

Losing Chandler definitely hurts. Losing Butler is not a problem at all, especially with Shawn Marion to pick up the minutes. However these two players had an open market value of over $20 million a season. The Mavericks have managed to replace their lost production for 1/3 the cost. What’s more, losing Lamar will definitely hurt the Lakers, who are a competitor with the Mavericks. There are definite concerns the Mavericks will have to address. They still need a center. Additionally their core of great players (Jason Kidd, Shawn Marion, Dirk Nowitzki and Lamar Odom) are all over 32 this season. It’s doubtful such a team can continue to play top basketball for many years. That said, this off-season the Mavericks are doing well. One or two other good moves and the Mavericks may very well see the Heat in the finals again.

-Dre

Wins Produced comes back better and stronger!

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Editor’s Note (i.e. Dre): The following is from Dave Berri, who is now too lazy to post his own stuff.

A New Wins Produced and A New Win Score
Find the new Wins Produced numbers at Wins Produced, which you’ll notice is on the navigation bar right above you!

Wins Produced was introduced and explained (not “more or less” explained, but explained in detail in the text and many tedious little end notes) in The Wages of Wins in 2006.  It was then discussed (with more math) in an article published in 2008, as well as in Stumbling on Wins (and in other places as well).

Both books argued that inefficient scorers in the NBA are overvalued and players that help in ways other than scoring are under-valued.  In other words, many players people think are great (or not great) are really not helping (or really are helping quite a bit).

Such an attack on “conventional wisdom” – a term introduced by the late John Kenneth Galbraith – didn’t make everyone happy.*  As Galbraith once noted, “Faced with the choice between changing one’s mind and proving that there is no need to do so, almost everyone gets busy on the proof.”

The “proof” some people constructed focused on the value of rebounds.  Because Wins Produced argues that non-scorers who grab many rebounds are quite valuable – and conventional wisdom argues that non-scorers are simply not that valuable – it must be the case that Wins Produced overvalues rebounds.

A variety of arguments have been offered in response to this critique.  Many of these were detailed in the Frequently Asked Question page. For example, it was noted that

  • although diminishing returns – as detailed in Stumbling on Wins — certainly exists for defensive rebounds (but not for offensive rebounds), the size of the effect is “small”.
  • to illustrate, when the impact of diminishing returns with respect to defensive rebounds is accounted for, the ranking of the players doesn’t seem to change much (a point made on the FAQ page).

As a consequence, Wins Produced has historically ignored this issue.

As the lockout dragged on and on, though, I began to think that maybe it might be better to just incorporate this effect into the measure we post at the WoW Journal.  After all, the effect has been measured and it can be included. So why not just make the adjustment and therefore remove the argument “Wins Produced overvalues rebounds” from the discussion.

So that is what I have done.  The specific calculations – which are somewhat more complicated than what was posted before — are detailed at the new “Calculating Wins Produced” website.

In addition, the measurements from 1999-00 to 2010-11 have also been posted.  Again, the results are quite similar.  There is a 0.98 correlation between Wins Produced as it was calculated before and the new measure that adjusts for what we see with respect to defensive rebounds.  In other words, the players who ranked towards the top of the league before still rank towards the top now.  And the same story is seen for the players ranked at the bottom.

To illustrated, here are the top 25 players once we adjust for the impact of defensive rebounds.

Rank Name Team Position Adj.P48 WP48 Wins
Produced		 Rank
Classic		 WP48
Classic		 Wins
Produced
Classic
1 Chris Paul New Orleans 1.00 0.401 0.309 18.4 3 0.335 20.0
2 Dwight Howard Orlando 5.00 0.498 0.301 18.4 2 0.374 22.9
3 Kevin Love Minnesota 4.22 0.500 0.335 18.2 1 0.457 24.9
4 LeBron James Miami 3.19 0.370 0.270 17.2 4 0.307 19.6
5 Dwyane Wade Miami 2.00 0.311 0.253 14.9 5 0.278 16.3
6 Pau Gasol LA Lakers 4.79 0.422 0.234 14.8 7 0.243 15.4
7 Steve Nash Phoenix 1.00 0.336 0.244 12.7 11 0.265 13.8
8 Landry Fields New York 2.00 0.295 0.237 12.5 6 0.304 16.1
9 Rajon Rondo Boston 1.00 0.327 0.235 12.4 18 0.243 12.8
10 Ray Allen Boston 2.00 0.263 0.204 12.3 22 0.185 11.2
11 Zach Randolph Memphis 4.31 0.381 0.212 12.1 9 0.263 14.9
12 Jason Kidd Dallas 1.00 0.305 0.213 11.8 14 0.247 13.6
13 Lamar Odom LA Lakers 4.00 0.368 0.212 11.6 13 0.249 13.7
14 Tyson Chandler Dallas 5.00 0.465 0.268 11.5 15 0.311 13.3
15 Al Horford Atlanta 4.75 0.390 0.203 11.4 16 0.230 12.9
16 Paul Pierce Boston 3.13 0.290 0.195 11.3 19 0.212 12.2
17 Kris Humphries New Jersey 4.00 0.411 0.254 10.9 8 0.353 15.1
18 Andre Iguodala Philadelphia 3.00 0.298 0.212 10.9 20 0.232 12.0
19 Kevin Garnett Boston 4.00 0.382 0.226 10.4 10 0.302 14.0
20 Manu Ginobili San Antonio 2.62 0.280 0.204 10.3 25 0.202 10.2
21 Derrick Rose Chicago 1.00 0.253 0.161 10.2 31 0.151 9.5
22 Nene Hilario Denver 5.00 0.405 0.208 9.9 28 0.208 9.9
23 Gerald Wallace Charlotte-Portland 3.00 0.263 0.177 9.9 17 0.230 12.9
24 Kevin Durant Oklahoma City 3.08 0.247 0.155 9.8 21 0.182 11.5
25 Blake Griffin LA Clippers 4.30 0.317 0.148 9.6 12 0.212 13.7

Previously the top player according to Wins Produced was Kevin Love.  Once we consider the defensive rebounds we estimate Love took from his teammates, Love is now ranked 3rd in the NBA.  Again, the two evaluations have a 0.98 correlation.  So although there is indeed a difference in the rankings, the difference isn’t very large.

Once this adjustment is made, though, we do need a new Win Score.  Previously each defensive rebound had the same value as a point, steal, offensive rebound, etc… .  Because we are taking into account how a player will take some defensive rebounds from teammates, the value of a defensive rebound will now be lower.  To ascertain how much lower, a model was estimated where a player’s WP48 was regressed on the following per 48 minute statistics (adjusted for position played): Points, Offensive Rebounds, Defensive Rebounds, Steals, Blocked Shots, Assists, Turnovers, Personal Fouls, Field Goal Attempts, and Free Throw Attempts.  From this regression we see that 98% of the variation in WP48 was explained by these statistics.**  Furthermore, the estimated weights yield the following Win Score model.

Win Score =             PTS + STL + ORB + 0.5*DRB + 0.5*AST + 0.5*BLK – TOV – FGA –                             0.5*FTA – 0.5*PF

Yes, the only real change is the value of defensive rebounds.  For 2010-11, the position averages for Win Score per 48 minutes are as follows:

  • Centers: 7.846
  • Power Forwards: 6.956
  • Small Forwards: 4.835
  • Shooting Guards: 4.104
  • Point Guards: 4.851
  • Overall Average: 5.729

If you wish to estimate WP48 for a player – and you don’t want to go through all the steps noted above (which are a bit more complicated than they were before) – one can take the following steps:

  • Calculate Win Score per 48 minutes for the player.
  • Subtract the position average noted above and add back in 5.729 (the overall average).  This gives you Relative Win Score per 48 minutes.
  • Estimate WP48 with the following formula: -0.07898 + 0.031888*Relative Win Score per 48 minutes

Of course, these steps aren’t necessary if you make it a point to keep visiting the Wages of Wins Journal.  Once the season starts we plan to have continuously updated values of Wins Produced and WP48 for each player.

- DJ

* – One should note that the argument that conventional wisdom in the NBA is incorrect is not unique to Wins Produced. As I argued four years ago, Win Shares and Adjusted Plus-Minus also argue that some scorers are overrated.  Not sure I recall anyone being that troubled by this aspect of Win Shares and Adjusted Plus-Minus.  One suspects that this is because the on-line stats community doesn’t devote much effort critiquing the models generated by members of the on-line stats community.

** – Using data from 2009-10, Win Shares per 48 minute was regressed on per minute values of Points, Offensive Rebounds, Defensive Rebounds, Steals, Blocked Shots, Assists, Turnovers, Personal Fouls, Field Goal Attempts, and Free Throw Attempts.  This regression revealed that 86% of the variation in Win Shares per 48 minutes was explained by the player statistics. That tells us that Win Shares has a much larger adjustment for team statistics.  Again, not sure I have ever seen anyone troubled by this feature of Win Shares.  Again, one suspects that this is because the on-line stats community doesn’t devote much effort critiquing the models generated by members of the on-line stats community.