People tend to think that those who prefer to see arguments based on numbers and statistical evidence are lacking in personality and a sense of humor.  In an effort to counter this perception, here is a joke David Tufte (a fellow economist at Southern Utah University) posted on his blog (VoluntaryXchange).  

A statistician’s wife gives birth to twins. Excitedly, he calls everyone to share the good news. When he tells the church they say, ‘That’s terrific! Bring them down to church this Sunday, and we’ll baptize them!’

’Uh, let’s just baptize one of them,’ says the statistician. ‘We can keep the other one as a control”.

Okay, beyond that one joke (which is just a sample of one for those keeping track), here is the latest podcast from Nerd Numbers.

http://www.nerdnumbers.com/podcasts/STAT_01_30_2011.mp3

as Dre notes, smart readers (like you) are using the RSS feed at:
http://www.nerdnumbers.com/podcasts/stat_feed.xml

(Advanced->Subscribe to Podcast in iTunes)

Here are some details from the podcast.  As Dre notes, I was a guest (along with Dre’s brother and Arturo Galletti). The conversation wandered from my plot to destroy basketball as we know it, childhood memories of the Incredible Hulk, and eventually a bunch of stuff on basketball.   If you click on the above link, Dre has posted a number of links that will make your listening even more enjoyable.  And as you listen, you will also hear some attempts at humor (although, often the attempts may not have been statistically significant — and yes, that attempt at humor was also not statistically significant).

And one should note, from this podcast comes the subject of my next post.

- DJ

Henry Abbott created quite the stir at TrueHoop on Friday.  In “The Truth about Kobe Bryant in Crunch Time”, Henry attacked a belief held by NBA decision-makers, the media, and fans.  The vast majority of these people appear to believe that Kobe is the best player in the clutch in the NBA.  Henry presented extensive evidence that this belief is not supported by much evidence. In fact, the extensive evidence Henry presents makes it clear that Kobe is simply not the best player in crunch-time.

It is not necessary to review all of this evidence here (if you haven’t already, go read Henry’s lenghthy column).  But one should note that

• since 1996-97, Kobe has taken 115 shots in the final 24 seconds of close games (teams within two points).  No one has taken more shots in this situation.
• Kobe has only hit on 31.3% of these shots, a mark eclipsed by many other players.
• Since Kobe arrived, the Lakers have had the best offense in the league.  But in crunch time – with Kobe on the roster – the Lakers are quite a bit worse (ranking only 12^th).

So, Kobe takes more shots than anyone else in crunch time. But he isn’t particularly good at making these shots and Kobe taking all these shots doesn’t appear to help his team.

This story appeared on the front page of the ESPN website on Friday.  So it is possible Kobe heard about this.  And on Friday night, Kobe had his first chance to respond.  And if Friday was his first response, it appears Kobe really wanted to confirm everything Henry was saying.

To see this, let’s review what happened in the last two minutes of Friday’s game between the Sacramento Kings and the LA Lakers. With two minutes to go in the game, the Kings led 95-90 and the Lakers had the ball. 

Here is how the Lakers’ possessions played out until the end of the contest:

@ 1:53 — Kobe misses 10-foot jumper (Pau Gasol rebounded the miss and then Shannon Brown missed a three-pointer)

After the Kings scored to make it 97-90…

@1:13 –Kobe misses a three-point shot

Omri Casspi of the Kings rebounded the miss but Tyreke Evans (with help from Lamar Odom) turned the ball back over to the Kings.  And then…

@0:49 – Kobe makes an 8-foot jumper to pull the Lakers within 97-92

After Samuel Dalembert is fouled and makes one of two free throws, Kobe Bryant draws a foul (while in the act of shooting).

@0:32 – Kobe Bryant makes two free throws

After Carl Landry is fouled and makes one of two free throws, the Lakers call a time-out. After the time-out…

@0:20 – Kobe Bryant misses a three-point shot

After the Lakers get the offensive rebound, Steve Blake misses a three-point shot.  After the Lakers get the offensive rebound…

@0:08 – Kobe Bryant misses a three-point shot 

After the Lakers get the offensive rebound, Steve Blake is fouled and makes one of two free throws.  After Pau Gasol rebounds the miss, Gasol misses a layup and Carl Landry of the Kings grabs the rebound.  Landry is fouled and makes one of two free throws.  The Lakers call time-out after the make, and then…

@ 0:02 – Kobe Bryant misses a three point shot.

Samuel Dalembert rebounds the miss and the game ends.

Okay, let’s recap. The Lakers are down by five.  But the Lakers had the ball and – according to conventional wisdom – were in great shape because they also had Kobe Bryant.  And here is what Mr. Bryant did to win this game:

• Of the Lakers nine field goal attempts in the last two minutes, Kobe took six of these shots.  Yes, Kobe likes taking shots at the end of a close game.
• On these six shots, Kobe scored two points for an effective field goal percentage of 17%. Yes, Kobe has problems hitting shots in close games. 
• Prior to the last two minutes of the game, the Lakers attempted 71 field goal attempts, and Kobe took 21.  On these 21 field goal attempts, Kobe scored 26 points for an effective field goal percentage of 62%.  Yes, Kobe is really good. In fact, he is a much better shooter when he is not playing at the end of a close game.

Once again, Henry’s story appears on the front page of the ESPN.com website on Friday morning.  That night, Kobe goes out and illustrates what Henry was saying.  In the last two minutes of a close game, Kobe decides to take the vast majority of his team’s shots.  And his ability to hit these shots is far lower than what we see across the rest of the game.

Henry’s post has generated more than 2,500 comments.  And one suspects, many of these weren’t nice.  One wonders, though, if any of the people who think Henry is a “Kobe-hater” (whatever that is) were impressed by what Kobe did on Friday night.  Or did this performance change their mind?

Okay, I doubt it changed many people’s minds.  Especially the minds of those “Abbott-haters”.

- DJ

Andres ‘Dre’ Alvarez — of NerdNumbers — offered a post this week that generated some attention. His discussion of the merits of Derrick Rose led a number of people to suggest that he start watching basketball.  In response to this argument, Dre offered the following at NerdNumbers (which is re-posted in its entirety below):

Just a note…what you are about to read is from Dre (in case that wasn’t clear).  And if you don’t have a sense of humor…. well, this may not be for you.

DJ over at the Wages of Wins Journal was kind enough to reprint my article. I love it when this happens, as his blog has a larger audience then mine. However, some of his commenters are not as nice as mine. The first response to my Derrick Rose piece was

“Statistics are useless. Watch a game. Then you understand why he should undoubtedly be in the All-Star game in a starting position.”

It turns out this argument is nothing new. “Just watch” is a silly argument when on any given night there are one to fifteen games on and over 500 hours of game time by the time the All-Star game comes around.

Let’s say hypothetically that I found the time to watch the best performance though of each player in the league. What would the All-Star Starters look like then? Well I was pleased with the answer and thought it was worth a post. So with that here are your 2011 All-Stars, providing of course you had the foresight to actually watch them play on their best night and of course don’t do something silly like look at their aggregate stats over the season.

Table 1: East Starting All-Stars based on their best game.

On the forward front the East looks right. Al Horford was a surprise to play in front of Dwight Howard, given Dwight’s rank on the best games lists. However the guard situation becomes much more amusing. The Derrick Rose, Rajon Rondo and Wade decision is gone, with John Wall and Stephen Jackson having the best games so far this season. I can’t imagine why fans of three such successful franchises as Boston, Chicago and Miami aren’t watching teams more than 10 games back in their spare time.

Table 2: West Starting All-Stars based on their best game.

I’m happy with the West because a Nugget I liked “legitimately” makes the cut. However, the West actually doesn’t look as good compared to the East using this model, which ironically mimics the real world. Love is an excellent choice, but the rest of the starters have not consistently been the best players out West this season.  Part of the issue with center is of course that many of the excellent centers out West (including Love) are listed at forward. Still, if the goal was exciting popular players, then the West hits at least two times.

I think many people vote for their favorite players (that is of course the point of the All-Star game) but feel offended when they find their favorite player isn’t everybody’s favorite. That said, no amount of clutch play, excitement factors, leadership and other such intangibles will do much to sway me from disagreeing with players like Kobe, Melo and to a degree Derrick Rose from starting over other players (or playing at all in Melo’s case). The other option of course is what I have done here, where I looked only at the stats I wanted to see to make my player look good. Most players have played 30-50 games at this point and using only one game to decide if they are All-Star worthy is silly. I’m willing to bet that most people usually only watch their home team play on a regular basis. Of course judging the entire NBA on a small set of games watched is probably silly as well, but apparently it is something people do.

-Dre

*Afflalo would have had to have been a write in vote, which is allowed.

This article uses the Wins Produced and Wins Produced per 48 minutes (WP48) metrics. These use the player’s box score statistics, the team statistics, and league averages to estimate how the player contributes to winning. An average player has a WP48 of 0.100. For a regular starter this would generate around 6.0 wins for the team in a full season of play. By contrast a “superstar” player has a WP48 of 0.250 and in the same minutes would generate around 15.0 wins for the team.



The Utah Jazz haven’t won a game since January 14^th, a streak of six consecutive games.   Prior to this streak, the Jazz were 27-13 and appeared to rank amount the top teams in the West. But after losses to Washington, New Jersey, and Philadelphia – below average teams in the East – fans of the Jazz wonder what happened to this team (and I know this, because I read about the Jazz each morning at breakfast).

The subject of what has happened recently certainly is interesting.  But before we try to understand the past few weeks, it is a good idea to gain some perspective by discussing the entire season to date. After 46 games, the Jazz have a record of 27-19.  When we turn to efficiency differential (offensive efficiency minus defensive efficiency), we see a team with a 0.4 mark.  This is consistent with a team that would win between 23 and 24 games across a 46 game schedule; or about 42 games across an entire season. In other words, the Jazz have won a few more games thus far than their differential suggests.

When we move from efficiency differential to Wins Produced – detailed in the following table – we can see who is responsible for these wins.

Deron Williams, Paul Millsap, Andrei Kirilenko, and Al Jefferson have combined to produce 22.3 wins thus far this season. Of the remaining nine players on the roster, no one has produced more than 1.3 wins.  So this team is the quartet of Williams-Millsap-Kirilenko-Jefferson, and  then, not much else.

The above table doesn’t just report what has happened in 2010-11.  It also reports what we should have expected had the veterans on this team maintained the per-minute performance we saw last year (or in the case of Raja Bell and Francisco Elson, what we saw in 2008-09).  As reported, the Jazz – given what we observed in the recent past – should have expected this collection of players to win 26 of their first 46 contests. Of these 26 expected wins, 23.0 can be tied to the play of Williams, Millsap, Kirilenko, and Jefferson.

Yes, the same quartet that is leading the Jazz this year was expected to lead the Jazz before the season started.  And the remaining players… well, the Jazz shouldn’t have expected much from them at all (which is what the Jazz have gotten).  All of this means the Jazz in 2010-11 are not really a puzzle.  This is a team that we should have expected to be a bit above average.  And this is what they have done.

Of course, the Jazz have not done well recently.  Surely this means something.

Well, maybe not.  Given what the Jazz players did last year, we could have expected these players – if performance didn’t change – to win between 40 and 50 games this season.  And that means, we should have expected the Jazz to lose between 32 and 42 games.  These losses, though, were not going to appear in a consistent fashion.  Sometimes average teams – or slightly above average teams – win a game, lose a game, and win a game.  But it is also possible for wins and losses to occur in streaks. When these streaks happen, we should be careful before we jump to conclusions.  Yes, the streak could mean something.  More often than not, though, one suspects these streaks are just part of how a team performs across an entire season.

Again, I noted the argument of Dean Oliver in Basketball on Paper.  Dean noted that a team that only wins 30% of their games has a 90% chance of winning three in a row at some point in an NBA season.  So streaks happen.  And when they happen, it doesn’t mean the team that is streaking has necessarily changed.

Despite this argument, people might want to look at player performance across the past few weeks and see if there is someone we can blame for this recent decline.  About three weeks ago I offered a post on the Jazz. At that time, the Jazz were 23-11.  Since this time, the Jazz have been 4-8.  When we look at the individual players, we can identify the players responsible for this outcome.

The following table reports the Wins Produced for these players across the past 12 games.

Given the minutes allocated, and the performance across the first 34 games, the Jazz should have expected to win about six games.  But the team only has produced about three wins, and one can easily see that the player who has declined the most is Paul Millsap.  Yes, Millsap is primarily to ‘blame’ for this recent decline.

However, Millsap is not the only problem.  Deron Williams should have produced about 0.8 additional wins across the past 12 games.  So we can ‘blame’ Williams as well.

Or can we?  Although we have numbers that say these players have declined, these numbers may not mean as much as we might think.

Consider the following about performance in the NBA:

• From season-to-season, a player’s ADJ P48 has a 0.83 correlation.  So from season-to-season, players are quite consistent (at least according to ADJ P48… per-minute Win Shares only has a 0.67 correlation and Adjusted plus-minus only has a 0.26 correlation).
• Performance across a season, though, is not constant.  Players tend to have good games and bad games.

For example, last night LeBron James had an effective field goal percentage of 29% against the Knicks.  And this is because the Knicks know how to play defense against King James.  And back on December 17 – when LeBron had an effective field goal percentage of 67% against the same Knicks – that is because the Knicks forgot how to play defense against LeBron.

Okay, I made up those explanations.  Again, performance from game-to-game, or even week-to-week, is not a constant.  Over time – as the sample size gets bigger and bigger – a better picture of a player’s productivity appears.  But over small samples, this picture is quite difficult to see.

Given the nature of small samples, we should be very hesitant to read anything in to what we see across a few games (or one game or a few minutes within a game).

So the last few weeks of Jazz basketball might mean that Millsap has forgotten how to be a productive NBA player and Williams has permanently declined from what have seen in the past.  Or it might just be part of the normal fluctuations in player performance across a long season.  The latter story seems more plausible, although probably not satisfying to those who want an explanation for every fluctuation we see in the data.

- DJ

The All-Star game is almost upon us.  This means it is time for the media to tell us who they think are the ‘best’ players in the game.  And it also means it is time for the people who look at stats to say “sorry, that player is not among the ‘best’”. 

So let’s get the season started with a comment on Derrick Rose.  Fans and media have fallen in love with Rose this year.  The Bulls are winning and Rose – who leads the Bulls in scoring – is clearly their ‘best’ player.  Andres Alvarez, though, disagrees.  What follows is a column he originally posted at Nerd Numbers, which makes two interesting arguments.  Rose may not be the ‘best’ but he may be another Kobe. 

Derrick Rose may be the new Kobe. By that I mean he’s a good player that people have definitely gone overboard on. Derrick Rose has been called a lot of things lately and one may question if they are true. The Automated Wins Produced Numbers can squash a few of these rumors. Derrick Rose is not currently in the top ten Wins Produced Players for the season. Derrick Rose is currently listed as the 7t^h best point guard in the league behind Chris Paul, Steve Nash, Rajon Rondo, Deron Williams, Jason Kidd and Russel Westbrook. It’s somewhat hard to even consider thinking of him as an MVP candidate with that in mind.

DJ at the Wages of Wins Journal sent me a question based on the recent podcast Arturo and I put on; Does Derrick Rose deserve to start in the All-Star game? An interesting thing about how Derrick Rose is perceived is that he has “ramped it up” since the start of the season and “become a leader” in light of the injuries to Boozer and Noah. With that I decided to take a quick look over the season piece by piece to get a slightly better understanding of Derrick Rose using the brand new Game Splits tool.

Table 1: Top Bulls throughout the season in 2 week increments.

At the start of the season Rose wasn’t very good. He improved slightly  for about two weeks before going back to merely being an above average point guard. For the first month and half of the season this team belonged to Noah. When Noah went down with injury it was problematic, but indeed Rose did step up his play and has been playing at star level since the start of December. However, it turns out that Boozer returning to the Bulls in top form was a bigger boost to the Bulls. In fact, it has only been in the last month with both Boozer and Noah experiencing injury that Rose is “leading” his team.

Let’s look at Rose in another light going in two week increments. Rose has been listed as an MVP and All-Star candidate. To be an honest option for All-Star I’d expect Rose to be a top 5 guard in the East at minimum. To be an MVP I’d expect Rose to at least be top 10 in the league. How has that looked?

Table 2: Derrick Rose’s rank as MVP, East Guard and Team Leader.

In December Derrick Rose did indeed crack the ranks of the top players in the NBA as well as play better than all the other guards in the East. Still, I think many would argue one week does not an MVP make. He was still second fiddle to Boozer though. Rose has only enjoyed one span of time as the “best player” on his team and it required the top two players to fall to injury. Rose as MVP and the best player on the Bulls looks a little weak to me.

One thing that doesn’t look so bad to me though is the All-Star possibility for Rose. In the last month and a half he has indeed been playing as a top guard in the East. The only real issue is that the three guards in front of him currently; Wade, Rondo and Fields are much better guards. So while I do consider Rose an elite guard out East I still can’t consider him worthy of starting the All-Star game.

Let’s make sure to end this on a positive note though. Derrick Rose has been playing like a star guard as of late. He is very easily worth his contract and if he keeps up his play will definitely be worth the extension the Bulls are likely to give him. To say Derrick Rose is not the best player in the league or the best guard out East or the best player on his team is not an insult. I am merely pointing out what others have said; that people are overreacting to Derrick Rose’s play right now. Derrick Rose is very talented and young and is a huge part of his team’s success. However, it would be foolish to give him all of the credit or consider him better than he really is.

-Dre

P.S. To make sure Arturo is happy, It should also be noted that the deserving starting point guard out East is playing better than Rose with fewer minutes and just as many team injury concerns on his team. Also Rose isn’t clutch. . .