About two weeks ago we volunteered to take questions from the readers at Freakonomics.com. The request for questions generated 60 responses.  Our responses – to ten of these questions – have now been posted.  So please check these out and let us know what you think (and we want to thank Freakonomics for the opportunity to interact with their audience).

Again, there were 60 responses and we obviously did not respond to most of these.  This is primarily because Stephen Dubner told us to focus on just a few of these questions (in fact he seemed somewhat worried that we might try and answer all of these).  Our answers run for about 3,000 words, so even though we only focused on a few, we wrote quite a bit.

Despite the volume of our writing, though, we thought there were still a few more questions we could answer.  So below are answers to five more questions from the Freakonomics readers (and some readers from here as well).

My question has to do with the BCS and college football:  Is it in the best interest of colleges to stick with the BCS system financially? How much would they lose from switching to a playoff system?   I don’t know if you specialize in professional sports, but I’m just curious.  — Erika

Can you estimate the financial impact of college football adopting a 32 team play-off? In college basketball the universities love the tournament so much they’re expanding it to 96 teams yet the same college presidents are scared of the financial impact of a football tournament – seems like the NCAA is speaking from both sides of their mouth. — Steve White

These two questions are related.  The NCAA and its member institutions generate most of its sports revenue from men’s basketball and football.  The outcome of each season, though, is different.  In basketball, the champion is determined by a tournament.  This tournament generates a tremendous amount of revenue, funds that are distributed to each of the members in the NCAA.  In football, the last game of the season – for the good and average teams – is a bowl games.  Proceeds from these games are distributed to the participants and to the respective conferences. 

From our understanding, if the NCAA adopted a playoff system for football – similar to what we see in basketball – revenues to the NCAA would increase.  But the revenues going to the top teams and the top conferences might actually decrease.  This is because we think revenues from a playoff system would have to go to all member schools.  Consequently, the top colleges are opposed to a playoff system.

One should add that the coaches are probably not that enthusiastic about a playoff system either.  Right now there are more than 30 head coaches who get to finish their season with a win in a bowl game.  If you go to a playoff system, only one head coach gets to be a bowl game champion.  And the other coaches get to answer questions about why their team isn’t as successful as their fan base desires.

Given these pressures, we suspect a playoff system for the top division of college football is not going to happen.
As for expanding the NCAA men’s basketball tournament… that seems more likely (although only a minor expansion is occurring this year).  Such a move would increase revenues for the NCAA and increase job security.  So on both fronts, the idea is a winner.

By the way, if you are looking for a good book on the economics of college sports, we would recommend “The Economics of Intercollegiate Sports” by Randy Grant, John Leadley, and Zenon Zygmont.

If there were one player action that you would want to be tracked and added to the NBA box score, what would it be?  — brgulker

Your work currently does not include charges taken by defensive players. Hoopdata.com now tracks charges taken and Tom Haberstroh has argued (rather convincingly) that taking a charge should be considered the same as stealing the ball because it forces a change of possession. Are you planning on re-running your regressions to find the value of box score stats with the addition of charges drawn? It seems like it would further increase the accuracy of the WP48 measure and better account for some aspects of individual defense, which the current system doesn’t totally account for (because of the limitations of the box score). Thanks!    — Kevin

These two questions go together.  The answer for brgulker is charges. Tom Haberstroh published a great article at ESPN on the importance of the charge in the NBA (insider access required).  This article clearly explains why we should track how often a player takes a charge.  And as Kevin notes, this data is available at Hoopdata.com (but it is not yet part of the standard box score).  To incorporate the data, though, one doesn’t need to run a new regression. 

As Stumbling on Wins notes, the basic regression employed involves regressing wins upon offensive and defensive efficiency.  From this regression we can see the value – in terms of wins — of points, field goal attempts, free three attempts, offensive rebounds, defensive rebounds, steals, turnovers, and personal fouls.  This model also provides values of the opponent’s turnovers that are not steals.  Part the opponent’s turnovers would include taking a charge, so this impact is already measured.  All one would need to do is download the data.

As for the other elements of defense, we also know – from the aforementioned regression – the value of an opponent’s scoring as well.  All we need is some method to assign this impact to individual players.  So far, though, the measures provided are not very stable over time. This suggests that defense in the NBA is primarily a team activity.  Consequently, defense is best evaluated at the team level.  One should note that most of the box score statistics are quite stable over time.  This suggests it is a good idea to credit these statistics to individuals.

Why haven’t the Cubs won a World Series in over 100 years? Do they keep making the same mistakes every year?  — Doug

Josh Peter – of Yahoo! Sports – wrote an article about the sale of the Chicago Cubs last fall.  In this article Peter addressed the Cubs reputation as “lovable losers.”  As the following quote emphasizes, this is really brilliant marketing.

“It is pure genius from a marketing perspective, that we support a team that is bad,” said David Berri, a professor at Southern Utah University who specializes in sports economics. “It’s the only entertainment where, ‘We have failed, but we would still like you to pay us.’

“Imagine if you had a restaurant like that. We serve crappy food! That’s what’s so great about us!”

As noted last fall, this is part of the problem in Chicago. Stefan Szymanski – author of Soccernomics (and a number of other books on sports and economics) – once estimated the link between wins and attendance for each team in Major League Baseball (in a paper presented at the Western Economic Association).  His results indicated that the fans of the Cubs are one of the least responsive to an additional win. 

So we would argue that one problem with the Cubs are the fans of the team.  The team knows the fans will show up whether the team wins or loses.  Since losing requires less money and effort, the team tends to be less successful.

One should add, a similar problem exists for the Detroit Lions.  The support for this team only started to falter when the team lost every game in one season.  Such loyalty is considered admirable by some.  But really, it just gives a team less incentive to try.

Your interesting inter-generational comparisons of NBA players reach back a little over three decades, a period for which you are able to use a full complement of variables to develop your models of player performance. Do you have any plans to develop models using fewer variables that would allow comparisons of players going back five decades or more? While the explanatory power of these more parsimonious models would almost certainly be lower, they it would allow for fascinating inter-generational comparisons — and would allow you to develop complete career wins estimates for players like Abdul-Jabbar, Julius Erving, and the like.  — Brian Taylor

This is an interesting idea.  The data presented in the standard box score goes back to 1977-78.  We can get everything except turnovers for the individual player (turnovers were tracked for the team) back to 1973-74.  So a few more years could be easily added, and those years would almost complete the careers of Abdul-Jabbar and Dr. J.

Before 1973-74, though, we don’t have steals, turnovers, or blocked shots.  But one could probably construct a measure from what we do have and tell some stories.  One would have to assume that the value of the statistics tracked is the same as what we observed from 1973-74 onwards. 

As noted, we do have measures back to 1977-78.  It might be a good idea to write another book detailing the stories this data tells.  Perhaps something like “An Alternative History of the NBA.”

Love the blog Dave.  Management make moves all the time with the implicit belief that they will be putting more fans in their seats and/or selling more tickets. These moves include player changes, coaching changes, management changes, adjusting game times, involving cheerleaders/dancers, promotions, and half-time entertainment.    Other than winning more games or (for teams that sell out) building more seats, is there any other act that has been shown to sustainably bring more fans into the building?  — TBall

Glad you like the blog.  As for your question… the factors that we find determine gate revenue include team performance (wins and wins last season), star power on a team (measured with all-star votes), arena capacity, age of stadium, being an expansion team, having won a championship (or championships) in the past, and employing a player taken with one of the first two choices in the NBA draft (in the past year or two).  Of these, wins, stadium capacity, and having a new stadium seem really important.

What is needed is a study of how all the other things a team does impact attendance.  That would probably make for an interesting marketing study.  From talking to people in sports, it is clear that they understand that winning is very important to their fan base.  But perhaps the half-time shows generate some fan interest.  It would be interesting to find out how much.

Final Thoughts

Even with these additional questions, we still have not responded to the majority of comments.  Hopefully we can get to more of these soon. 

Let me close by noting that none of these questions at Freakonomics apparently came from the APBRmetrics community.  Members of that community, though, did comment on the Q&A.  I will leave it to members of this community to think of an appropriate response. 

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

Wins Produced vs. Win Score

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.

Once again an award has been given by the NBA. And once again, the leading scorer eligible for the award is the winner. Tyreke Evans – who led all rookies with 1,450 points scored – has been named Rookie of the Year.  Stephen Curry – who finished second in scoring – finished second in voting.  And Brandon Jennings – the third leading scorer – finished third.

When we move past this one element in the box score and consider a player’s production of wins we see that Evans and Curry are… okay, they are still the top rookies.  Curry produced 9.1 wins with a 0.151 WP48 [Wins Produced per 48 minutes].  And Evans produced 8.9 wins with a 0.159 WP48.  So one could argue that either player was the most productive rookie, and therefore, this is not quite the familiar story we always see.  Yes, the scorers were given the award.  But since a scorer can produce wins, the writers would have come to the same conclusion whether they looked at scoring totals or all the elements of the box score.

At least, that’s true if you just look at Evans and Curry.  If we move further down the list we see two scorers who are not as productive. The first is Jennings.  Of those receiving any consideration for this award, Jennings is the only one still playing.  Across the regular season, though, he only produced 3.8 wins with a 0.067 WP48.  Yes, Jennings can score.  But he is not yet producing wins in large quantities (at least, not in the regular season).

Jennings, though, is much more productive than Jonny Flynn.  With the 6^th pick in the 2008 NBA draft, the Minnesota Timberwolves selected Flynn.   And although he finished fourth in scoring in this rookie class – and earned two third place votes for Rookie of the Year — Flynn finished the season with -1.4 Wins Produced and a -0.030 WP48. 

It’s interesting to note that every rookie who received consideration for this award was drafted in the first round.  DeJuan Blair produced 7.9 wins with a 0.255 WP48.  And Jonas Jerebko produced 6.0 wins with a 0.128 WP48.  Neither player, though, received even a third place vote for Rookie of the Year.

The voters focus on first round picks led me to wonder: How does the first round of the 2009 draft look now that we have seen these players for one year?  For an answer we turn to Table One.

Table One: Reviewing the First Round of the 2009 Draft

From Table One we can see the Wins Produced and WP48 of each player taken in the first round (with the exception of those that did not play).  As one can see, only four of the rookies taken in the top ten finished in the top ten in Wins Produced.  Blake Griffin and Ricky Rubio didn’t get a chance to play.  And the minutes of Hasheem Thabeet and Jordan Hill were limited.  But DeMar DeRozen and Flynn, didn’t perform well.  And given what each player did in college, this is not surprising.

When we look at the entire first round we do not see much of a link between where a player was drafted and his first year performance.  In this small sample, the correlation coefficient is only -0.22.  This is actually a similar result to what we report in Stumbling on Wins (where we looked at a much larger sample of players across more than just the first season of a player’s career).   NBA productivity and draft position simply do not have a very strong link.

This is similar to what we see for quarterbacks  in the NFL.  The reasons, though, are different.  Much of what we know about a quarterback before the draft (i.e. most college stats and the combine data) is not correlated with future performance.  This means choosing quarterbacks on draft day is really quite difficult (more on this in a near future post).  There is a relationship, though, between what players do in college and what they do in the NBA.  It is not a perfect relationship.  But there is a statistical link.  Despite the link between college and professional performance, though, NBA decision-makers make more mistakes than expected on draft day.

Much of this is due to a very familiar story.  Yes, too much emphasis is placed on scoring.  Scorers like Jonny Flynn tend to go first.  And these players don’t always produce many wins.

Let me close by noting again that scorers can certainly produce wins.  Evans and Curry were the most productive rookies.  And LeBron James – a very prolific scorer – was the both the Most Productive Player (MPP) and MVP.  More on that story in a future post.

- 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

Wins Produced vs. Win Score

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.

Here is a fun story from David Biderman of the Wall Street Journal.  In “LeBron’s So Great, Can We Share Him?” , Biderman asks an interesting question:  What if the Nets and Knicks both hired LeBron for next season?  Biderman went through the schedule and established that it’s possible for LeBron to play 41 games for each team.  Such a schedule would dramatically limit LeBron’s travel time.  And “Thanks to some statistical wizardry from sports economist Dave Berri, who has developed a way to measure how much an individual player’s contributions on the court affect his team’s wins and losses, it’s even possible to get a rough fix on how the two teams would have fared.”

My calculations involve looking at how LeBron would have impacted each of these teams in 2009-10.  To see these calculations, please click on over to the article.

- DJ

This story sounds very familiar, so I will make this brief. Jamal Crawford was the overwhelming choice of sportswriters for the 6^th Man Award.  Of the 122 sportswriters who voted, 110 chose Crawford for this award. 

The official press release from the NBA explains why Crawford was so popular with the voters.

Crawford, Atlanta’s second leading scorer at 18 points a game, led the league in that category among players who didn’t start a game and paced the team in scoring 27 times.

So once again, scoring dominates an NBA player evaluation.

According to the above press release, this award works as follows: In order to be eligible, players had to have come off the bench in more games than they started. Players were awarded five points for each first-place vote, three points for each second-place vote and one point for each third-place vote.

Last season, 268 players were technically eligible for this award.  From this sample of players, Table One reports the top 40 in terms of Wins Produced.

Table One: The Top 6^th Men in 2009-10

Topping the list is Lamar Odom, who did receive one first place vote and consideration from nine of the 122 sportswriters.  In other words, Odom was ignored by 113 voters.  More sportswriters paid attention to Manu Ginobili.  But the winner of this award in 2008 only received votes from 33 of the participating writers.

Much more attention was paid to Jason Terry, who won the award last season.  Only 22 sportswriters didn’t think Terry deserved consideration this season.  What does Terry do to deserve such love from the writers? Yes, like Crawford, Terry is also a scorer.

There is some hope.  Anderson Varejao is not considered a scorer.  And two sportswriters thought this particular non-scorer deserved the award.  Furthermore, 52 more writers – or about 44% of the total – thought Varejao ranked in the top three among all 6^th men.   Maybe in a few years (or decades), players like Varejao – who produce many wins without scoring – will get a level of attention from sportswriters that is proportional to their productivity.

Let me close by noting that I have completed my analysis of every player in the 2009-10 regular season.  So as each player award is announced I will be offering similar comments.  And I will also be offering reviews of the 2009-10 regular season for each individual team.  These posts should be the primary offering this summer.

- 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

Wins Produced vs. Win Score

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.

I am scheduled to be on ESPN Radio in Milwaukee at 3:40 EST (yes, in about 10 minutes).  We will be discussing the Milwaukee Bucks (and Stumbling on Wins). Sorry for the short notice on this.  Here is a link to the website where you can listen live.

540 ESPN Milwaukee

- DJ