Wins Produced was developed as a method to assign the credit (and blame) for what we see at the team level in basketball to the individual players (such a method is important for some research in sports and economics). We know how much a team has won. What we want to know is which players were responsible for that outcome.
For example, consider the Chicago Bulls last season. The Bulls finished the 2007-08 season with 33 victories. When we look at Wins Produced – reported in Table One — we see that Luol Deng’s 6.0 Wins Produced led the team. Ben Gordon – who led the team in scoring (and his agent used this fact to demand a significant increase in pay) – only produced 2.7 wins. In essence, Deng was twice as productive as Gordon.
Table One: The Chicago Bulls in 2007-08
Although this observation is interesting (or not), when we look at this particular team we have to ask a more important question:
What the hell happened last year?
In 2006-07 the Chicago Bulls won 49 games, which is pretty good. The team’s efficiency differential (offensive efficiency minus defensive efficiency), though, was 5.2. Such a mark is consistent with a 54 win team (which is even better).
Virtually all of these 54 Wins Produced could be traced back to players who Chicago employed in 2007-08. Additionally, the Bulls added Joakim Noah. Given what Noah did in college it was expected that he would contribute as a rookie. And as Table One indicates, Noah was above average in 2007-08.
When you add an above average rookie to the collection of veterans Chicago employed in 2006-07, it’s not a stretch to state (as I did last September): … just looking at what this roster did in the past – which is a good but not perfect predictor of the future in the NBA – Chicago fans should expect a team that surpasses 54 wins. And that means the Bulls – or Da Bulls – have returned.
After the first month of the 2007-08 NBA season, though, it was clear that something was wrong in Chicago. The team’s record after November was only 3-10. The team’s efficiency differential was -8.5, a mark consistent with a very bad team.
Back in December both John Hollinger and I (in separate columns) noted the problem. Chicago was not hitting its shots. To illustrate this point I produced three projections of Chicago on December 1, 2007.
Table Two: Projecting the Chicago Bulls (from December 1, 2007)
Here is how these projections were summarized last fall: … had each Chicago player maintained what they did last year, the Bulls would be on pace to win 57 games. …What happens if all we only utilize shooting efficiency from 2006-07, but keep everything else as it is in 2007-08? Now we see the Bulls would be on pace to win 55 games. Yes, virtually the entire problem this team has is tied to shooting efficiency. If this problem were solved, this team would start winning again.
So after one month, the Bulls problem was identified. The ball was simply not going in the basket that often. Consequently this team was losing.
As GI Joe would say “knowing is half the battle.” Unfortunately when we look at the final numbers for the Bulls, it doesn’t appear the team made much progress on the other half of this battle.
Table Three: The Chicago Bulls with 2006-07 and 2007-08 numbers
During the 2007-08 season the Bulls fired their head coach. They also were part of a major trade with Cleveland and Seattle that saw the Bulls acquire Drew Gooden, Larry Hughes, Cedric Simmons, and Shannon Brown (for Ben Wallace, Joe Smith, Adrian Griffin, and a second round draft choice in 2009).
Despite all these moves, though, the Bulls didn’t improve substantially. They certainly weren’t able to get back to the promise of 2006-07.
Table Three indicates that given what the veteran NBA players Chicago employed in 2007-08 did in 2006-07 (and this includes the players acquired in mid-season), the Bulls should have expected to win 49.4 games last year. In other words, they should have been as good as they were in 2006-07.
Instead, as noted earlier, the team only won 33 games. Returning to the shooting efficiency story we saw last December…. if Chicago’s returning players managed to maintain the same level of shooting efficiency we saw in 2006-07, Chicago’s projected wins rises to 44. In sum, just as we saw after just one month, Chicago’s problems at the end of the season were stilll primarily tied to a decline in shooting efficiency.
How, Why, and Derrick Rose
It’s important to emphasize that numbers allow you to assign credit and blame. The numbers allow you to see how productive a player has been, and where this productivity has changed. But the numbers are a bit fuzzy on the question of “why”. In other words, we can see the impact a change in shooting efficiency has on the success of the Bulls, but the numbers are not going to tell you why Luol Deng, Kirk Hinrich, Chris Duhon, Andres Nocioni, Ben Gordon, and many of the other players employed by Chicago were not hitting their shots last year as well as they did in 2006-07.
It is apparent when we look at the data that the shooting problem appeared very early in the 2007-08. And it doesn’t appear that this problem was ever fixed. Now the Bulls have drafted point guard Derrick Rose. At this point it’s not clear yet that Rose will help. It’s not even clear that he will be a productive pro (it also isn’t clear yet that he won’t). We should note, though, that despite the shooting woes of Hinrich and Duhon (the latter moved on to New York), each of these veteran players was close to average last season. And rookies tend to be below average. So Rose may not help much immediately. Still, nothing else the Bulls did worked last year. So why not take a shot with Rose?
Keeping Gordon?
Beyond the addition of Rose – and loss of Duhon – the Bulls are returning virtually the same team that ended the 2007-08 season. The lone exception might be Ben Gordon, who currently is unsigned.
As I noted earlier, his agent has argued that since Gordon was the leading scorer on the Bulls last year, Gordon should be the highest paid going forward. When we look at Wins Produced, though, it is clear Gordon’s productivity is inconsistent with the money he is demanding. In fact, given Gordon’s lack of production, it’s not clear that the Bulls should even bother signing Gordon to the offer the team has already made. So what should the Bulls do?
One possibility has been offered by Steve Luhm with the Salt Lake City Tribune. Luhm has suggested that Utah offer Andrei Kirilenko and Ronnie Brewer for Gordon. As noted a couple of weeks ago (in a post titled — Note to the Media), Kirilenko and Brewer were well above average for the Jazz last season. So such a suggestion – from a Jazz fan (I suppose) — would definitely help the Bulls (and hurt Utah).
Barring such a trade (which I can’t believe Utah would do), the Bulls will probably enter 2008-09 with Rose and much of the roster that finished 2007-08. If we look back at 2006-07, such a roster could be very competitive. If what we saw in 2007-08, though, is the future for these players, then “Da Bulls” are not going to be seen again anytime soon.
One last note on Gordon…Gordon, relative to 2006-07, was a less efficient scorer in 2007-08. Relative to the other players on Chicago in 2007-08, though, Gordon was one of the most efficient scorers on the Bulls. This fact, though, does not increase Gordon’s value. The proper comparison is not Gordon’s shooting relative to the rest of the Bulls. No, a better comparison is to look at everything he does (including shooting) relative to the average shooting guard in the league. And by that comparison, Gordon should not be the highest paid player on this team (or any other team).
– DJ
The WoW Journal Comments Policy
Our research on the NBA was summarized HERE.
The Technical Notes at wagesofwins.com provides substantially more information on the published research behind Wins Produced and Win Score
Wins Produced, Win Score, and PAWSmin are also discussed in the following posts:
Simple Models of Player Performance
What Wins Produced Says and What It Does Not Say
Introducing PAWSmin — and a Defense of Box Score Statistics
Finally, A Guide to Evaluating Models contains useful hints on how to interpret and evaluate statistical models.
Wages of Wins Journal 
mrparker
August 29, 2008
From what I saw the Bulls turned into a jump shooting team. I spent quite a few weeks in December and January yelling at my tv every time I watched the Bulls offense stagger through 2 bad passes followed by a fade away jump shot followed by Andres Nocioni running up and grabbing the rim but not getting an offensive rebound followed by the other team going on a fast break. That sentence structure was meant to be a metaphor for the structure of the Bulls offense.
It just “looked” like they didnt enjoy playing together.
My two cents.
Tball
August 29, 2008
There should be a way to investigate the change in shooting efficiency more thoroughly. Have other teams without significant roster turnover suffered similar changes in shooting efficiency year-to-year? If so, how did they bounce back?
In baseball, batting averages are more prone to single season aberations than isolated power or plate discipline. Is shooting efficiency similar?
Did other parts of their offensive game suffer that might shed added light? Assists/FGM? Offensive rebound%? Percentage of shots attempted in the paint? Number of 3PTA? Fast break PPG? If this type of fluctuation is uncommon, then you would expect an underlying conscious decision is at the root (e.g., slowing the game down [when fastbreak points provide a higher efficiency], players playing for contracts playing more one-on-one, retreating from the offensive boards to play better defense, etc.)
Throwing our hands in the air and saying this could be a 55 win team or a 30 win team is fairly unsatisfying for predictive analytics.
stephanie
August 29, 2008
I don’t think anyone pegged the Bulls as declining like they did. Every account I read believed they were going to go deep into the playoffs last season. It was unfortunate they became so miserable since they appeared on national television so many times. And the East could always use more good teams.
Speaking of Chicago, I’d be interested in seeing how WP explains the Bull’s record in terms of crediting wins before and after the third title. In 92-93 they’re 57-25 with an efficiency differential of 6.8. MJ averages 32.6 ppg / 6.7 rpg / 5.5 apg / 2.8 spg on 49.5% shooting. That’s good for what, somewhere between 17-20 wins? Then he retires. In 93-94 the Bulls are 55-27 with an eff. def of 3.4. Apparently without MJ their offensive efficiency drops like a stone (2nd to 14th) but they only lose two less games. How does that work out? I’d be really interested in seeing Horace Grant’s numbers throughout all of this too. I’m thinking he was a large piece of the pie.
Owen
August 29, 2008
Stephanie – You should buy yourself a copy of the Wages of Wins!
Mountain
August 29, 2008
This Bulls example can be used to assert that coaching- most significantly thru lineup and play calling decisions- and chemistry matter a lot and players don’t always just deliver individual contributions that largely carryforward year to year.
In 06-07 Skiles used his top 2 lineups almost 1000 minutes (close to 25% of total minutes) and only won about 40% of that time. But Skiles pushed the right buttons for which lightly used lineups to play the other 75% of time and they made that season a success.
In 07-08 it was some combination of he and his replacement apparently not pushing the right lineup and play buttons and players not performing. Sorting out shares is hard but with more research on each lineup usage and performance year to year some level of handle might be possible
The Bulls only used top 2 lineups only about one-third of previous year) and they weren’t especially strong.
Maybe the league figured out play calling patterns and defending those lineups (and exploiting them) more than Bulls figured out how to adjust to the adjustments.
They had some promising performances from small minute lineups but apparently didn’t chose to try to milk them. No guarantee they would continue to work at same rate in more minutes but I’d think they probably could have tried the best lineups more. Like most teams.
Joe
August 29, 2008
stephanie,
As Owen said, that specific topic is covered in the book. He tells several “Chicago stories.”
Owen
August 29, 2008
As the disappointed owner of Luol Deng in a fantasy league, I think its important to mention that he struggled with injuries all year.
I would love to know from any Chicago fans out there what the heck happened to Hinrich.
Mike G
August 31, 2008
Aren’t there 2 “what the hell happened” questions?
One is why Bulls underperformed.
But the other is why your model underperformed.
Los
August 31, 2008
Kirk had a hurt back, and he was trying to play through it- which is probably why his shot was deathly flat to start the season.
richardjamesuk1981
September 9, 2008
Ok being a Bulls fans since the MJ days
The current team haven´t got the heart apart from Luol Deng, and now Derrick Rose, and i believe Drew Gooden is going to have a decent year, he played very well till the end of the year and unfortunately got injured….
I think he can be out horace grant which we have missed since elton brand..
Kirk Hinrich missed too many shots and in my opionion should have been traded, not Duhon got rid of.
I think the Bulls maybe closer to the playoffs but they need to concentrate on defence and that is where the Bulls suffered last year which was a surprise as i believe the year before the had one of the best defence records in the NBA , so without Wallace is Noah goign to take his place? HMMMM
Del Negro is a rookie coach and I don´t believe he has the skills and only his coaches around him may help this, but i think Ben Gordan will cause problems so i hope he wil traded for a decent guard, who? i am not too sure but i would like either Chauncey Billups or Michael Reed we can thorw in larry hughes with gordan and hinrich, or Dwanye Wade when he is a free agent next year
Any suggestions