Researchers' NBA officiating study detects biases, but not necessarily the ones fans suspect
by Rachel Bachman, The Oregonian
Wednesday June 03, 2009, 5:24 PM
Los
Angeles Lakers coach Phil Jackson argues a call with official Bill
Spooner during Game 1 of the Lakers' first round series with the Utah
Jazz.But the same study found that NBA referees tend to favor home teams, teams trailing in a game and teams trailing in a playoff series.
The study, conducted by three economics researchers, fuels the perennial debate about the influence of NBA officials on games. It suggests that forces ranging from league executives to simple human psychology can influence calls in a measurable way -- though not always enough to affect a game's outcome.
The researchers looked at six seasons of turnover statistics. They used ones where referees wield relatively little influence, such as a bad pass or steal, as a "control" group, and compared them with ones where referees wield greater influence, such as traveling and offensive fouls.
The researchers found that each type of favoritism -- home, trailing in a game and trailing in a series -- resulted in a 5 to 10 percent advantage in "discretionary" turnovers, or ones over which referees have the most influence. The researchers do not attempt to explain what the percentages could mean in actual wins and losses.
Still, the study concludes that the detected referee biases, though probably unintentional, could increase the league's revenues through additional ticket sales and television appearances by reducing the number of blowout games and making televised games more compelling.
"We can say with fairly high confidence that the results are not just due to randomness or (statistical) noise, that even teams facing elimination have an additional advantage in these referee-based turnovers, discretionary turnovers," said Daniel F. Stone, assistant professor of economics at Oregon State University and one of the study's authors.
NBA executives condemned the study, which is dated March 2009 and has not been published in a scholarly journal, criticizing its methodology, tone and conclusions. The league, whose showcase event, the Finals, starts tonight with the Los Angeles Lakers hosting the Orlando Magic, rigorously monitors officiating and does not condone favoritism, said Joel Litvin, the NBA's president of league and basketball operations.
Litvin also dismissed the study's suggestion that fans influence referees' behavior, a finding that echoes those in research about European soccer. The basketball study finds that the home-team advantage in discretionary turnovers increases by 1 percent for every 1,000 people in attendance.
Based on that figure, when the Trail Blazers ranked third in the league in average home attendance last season at 20,524, they should have received more than a 5 percent advantage in discretionary-turnover calls over the 2005-06 season, when they were last in the league with 15,049.
Litvin responded that NBA officials are the best in the world, reaching the league through superior skill and imperviousness to criticism.
"I do believe, and I think it's the case," Litvin said, "that these people are, in fact, immune to the things that you and I would say are just human nature."
Study genesis, response
Stone and fellow graduate student Marc Remer decided while at Johns Hopkins University in Baltimore last spring to test the popular conspiracy theory that NBA officials favor teams facing elimination to extend a playoff series.
Stone and Remer recruited help from Joseph Price, an assistant professor of economics at Brigham Young University who co-authored a study publicized in 2007 that found that NBA officials tend to favor players of their own ethnic backgrounds.
After collecting data for the latest study, culled from play-by-play accounts on ESPN.com, the researchers stumbled into the "home" and "close-game" bias findings, Stone said. Price said the study's most interesting conclusion is that officials might exhibit biases -- conscious or unconscious -- that could benefit their employer.
The researchers also found foul advantages for home teams and teams trailing in a game, but did not emphasize them in the study.
"Our results on fouls are weaker since we can't draw the same distinction between whether they're referee or player-driven as we can for turnovers," Stone said.
NBA referees are paid salaries during the regular season and also for each playoff series they work, according to a league spokesman. So they have no apparent financial motivation to make calls that would extend a playoff series.
Referees must be selected to work the playoffs, however, and are chosen based on experience and regular-season and playoff performance, which is evaluated by league and team officials.
More playoff games typically produce more ticket and television revenue for the NBA. Consequently, officials could make calls to enhance those revenues in order to please their employer, the study says. It also says referees "may have made calls in attempts to please the crowd or players, without being cognizant of their effects on league profitability."
Litvin called the suggested link between referees' calls and league profitability "preposterous."
"But people still think we fixed the Ewing lottery, so I guess nothing surprises me," Litvin said. The 1985 draft lottery gave the large-market New York Knicks the No. 1 pick (and superstar college player Patrick Ewing) despite one-in-seven odds. Wild speculation surfaced that the league froze or bent the Knicks' envelope to make it identifiable by touch.
For five years, the NBA has used observers to log and scrutinize every call. It amplified its study of certain calls in the wake of referee Tim Donaghy's 2007 guilty plea to criminal charges in a gambling scandal involving games he worked and bet on.
"It's really a matter of whether or not the referees are correct in their calling," said Steven Angel, the NBA's senior vice president of league operations and officiating. "And we find that they are."
Although the executives said the league's vast data set is sortable by nearly any category, they declined to release all or a portion of that information, even with officials' names omitted. Litvin said the data are private, and that releasing them would not quell speculation anyway.
Study shortcomings, strengths
The study comes with caveats. Referees' tendencies as identified in the study do not determine what might happen in a particular game or playoff series. And even if bias is detected, it's nearly impossible to determine why it's happening.
The study also has not been accepted for publication, a process that includes a robust peer review. It was declined by the first journal to which it was submitted, though academic articles often are rejected by several journals before being accepted. The journal's editor said he does not comment on specific submissions.
Randy Bluffstone, professor of economics and department chair at Portland State, reviewed the study at The Oregonian's request and found it to be generally rigorous and relevant, especially given the frequent fan discussions of NBA officiating.
"I think the work is, in the main, quite well done," Bluffstone said. "The thing I just don't see is big effects. We can be really sure that they exist, but they're pretty small."
The home-team advantage, for instance, would yield about one extra turnover every three games, Bluffstone said.
He also called the study's detected advantage for a team trailing in a playoff series "statistically insignificant."
One of the study's findings most notable to fans, ironically, appeared in a footnote: that teams from large media markets received no strong favorable treatment during the playoffs.
"Our evidence for that is weak in either direction," Stone said. "It's not like we're proving that that bias doesn't exist, either."
The study notes that it did not examine another fan theory -- that referees favor star players -- because the researchers chose to focus on team-related biases.
Bruce Blonigen, Knight professor in social science in the University of Oregon's department of economics, also reviewed the study at The Oregonian's request. He praised its detailed data (taken from about 3,500 games, from 2002-2008) and the use of "non-discretionary" turnovers as a control group.
"All in all, I find their analysis very compelling and would not be surprised to see it land in a top economics journal," Blonigen said.
The study concludes with suggestions for the league, including increased monitoring of discretionary fouls, clarification of the rules and inclusion of traveling and offensive-foul violations in box scores.
It's unlikely the NBA will consider the suggestions any time soon. Said Litvin: "We don't plan to engage the authors."
Rachel Bachman: 503-221-4373; rachelbachman@news.oregonian.com
Typical league defenses. I don't know of a single entity out there that is going to say that their officiating, or in the business world their internal controls, are not up to par.
However, that is exactly what the media and fans want to hear, honesty. Good luck getting it from this or any other business.
I don't think that is very hard to realize that home teams are obviously favored in calls by referees. I need only to use Cleveland vs. Orlando games 5 and 6 as an example. Although impossible to statistically prove, star players are also given much more room to commit contact and not draw a foul than are non-star players. A good example would be how Yao and Howard consistently bumped players on their way to the basket with no foul called, yet Oden and Bynum consistently are called for fouls on the same bumps.
This is a flawed study. They don't even talk about ref protection of superstars, and ref dissing on rookies and young players and its impact on games, thus this is a referee bias. Somebody in the story was quoted as saying that the NBA refs are the best in the world and that they are even beyond reproach with the factor of human imperfections thrown in. WTF? what planet is that guy on?
This article was not written specifically for the internet...The finals will start the day this is posted in the oregonian....tomorrow
Finally some confirmation of what all the level headed fans already knew. There is no big conspiracy, you mostly make your own luck, and the best players and best teams usually win. I get so sick of reading how the refs hate us when we lose, and silence when we win. Refs (Tim Donaghy aside) have no reason to favor one team over another and the games almost always seem fairly called overall. As the refs get used to Oden, his lifen will get easier. Remember, Shaq couldn't buy a foul call his rookie year. Second year, he got to the finals. It'll come.
Come on NBA fans! Ignore what you keep seeing year-after-year and game-after-game. The games aren't fixed. Instead, the officials just innocently keep making amazingly unbelievable bad calls that favor the home teams, "stars," and Mr. Momentum.
Rule Book? They don't need no stinking Rule Book!
You'll find more Integrity and Consistency in Congress (OMG!) than the way games are officiated in the NBA.
The NBA is simply Big Business ENTERTAINMENT performed in a basketball venue. All the league really cares about is that people watch and buy jerseys.
Screwing officiating keeps people booing, complaining and talking. And as long as NBA fans keep buying tickets and watching TV games, the NBA office and owners and players will keep laughing all the way to the bank...
"NBA refs are the best in the world..." Litvin said. Keep guzzling that cool-aid NBA fans. It's Fantastic!
We don't need a study to show that the refs can change the outcome of a game.
In the NBA(I don't watch other basketball, so I don't know), the refs choose whether to enforce, not enforce certain rules. Sometimes, it's no blood, no foul. Sometimes, literally, you look at somebody hard, it's a foul. Yes, sometimes by mistake, but sometimes not.
To getadog, I complain either way. Some of the officiating during the Blazer wins are ridiculous. Over the years, I've seen games where the refs don't even give one of the teams a chance. They, not the defense, effectively take the post & the lanes away. If your team's not hot from outside, tough luck.
Lastly, most fans can see the politics in the calls made. NBA refs call it "benefit of doubt". I call it bias. Some fans defends this whatyoumightcallit by saying that the superstars/veterans, they earned those calls. No, they should be earning it by getting fouled. Not because of they are all-stars, or they've been in the league longer. Any other way, it's an uneven playing field.
Personally I agree with UO75grad, a6m5 and PHANTOM11. I feel like refs consistently change the outcome of games whether they mean to or not. Calls effect the way people play, agrressive or passive-drive or shoot. Anyways, ive seen good and bad calls for us and against us. I still think the NBA needs some kinda replay system similar to the NFLs challenge play.
Good job with that study, guys. Here's your check. Oh, did you make sure to alert all the publications about the study that I had on that list I sent you? They'd probably all be interested in it, I'm sure.-- David Stern
'blazzed'
Next time, know what you're talking about before you take a cheap shot about game time...this is appearing in Thursday's paper -- game night!! Back to your bong...
if the nba is so certain about the quality of their refs why don't they have a little more transparency on this issue? SHOW us how you review their performance, MAKE them accessible to the media. My god, at least you'd get some people off of your back. and I don't think the majority of people are claiming the league is rigged, I think most people are just saying your refs are stupid and bad at what they do. Its a hard job, yeah, but it certainly seems that referee performance could be improved...of course we'll never get to know because the league won't acknowledge there is a problem.
There has been a bias in the NBA for at least the last 20 years. Primarily towards superstars and I believe to a lesser extent for the home team.
I can recall when Clyde Drexler was in his rookie year and was guarding Moses Malone on an in bound pass. Malone shoved Clyde to create seperation before the ball was thrown in. Clyde looked at the ref, who was standing next to Malone and Clyde and looked at him as if saying "didn't you see what he just did" the ref in return gave him a look that said "just play on." There would be no way Clyde could have done that to Malone and not gotten a call.
The NBA knows fans come to see the superstar play and they ideally don't want them in foul trouble. They also know fans are more likely to come out and watch their team if they think they are going to win (I do believe however that giving calls to the home team is more human nature then a built in bias by the NBA).
Lebron James averaged 1.8 fouls a game this season - he plays a physical game and I've seen him literally run over players who have held their ground (out of the circle under the hoop) and no call has been made.
This bias has made it hard for me to want to watch some of the better players play - I ended up turning off the first game of the Cleveland vs. Orlando series after watching Lebron get away with things no one else on the court could and even though I think Lebron is a tremendous player, and have nothing against the Cav's, I found myself pulling for Orlando for this reason.
I don't believe Stern/NBA is speaking with integrity when he/they deny there is a bias towards the superstar player, or the home team as a whole, doesn't get the benefit of calls. It's kind of like Major League baseball for years saying there isn't a steroid problem - say what you want, but the evidence is often easy to see.
Orygun101 and others...
Read more carefully. The researchers specifically excluded certain elements from their study, mainly because they are very subjective items that are very difficult to quantify. Those include things like favoritism for super-stars and the like.
That doesn't say they don't happen, it simply says they are very difficult to study objectively. I agree that the league's blanket denial of what they did study is tough to accept.
WWM
Orygun101 and others...
Read more carefully. The researchers specifically excluded certain elements from their study, mainly because they are very subjective items that are very difficult to quantify. Those include things like favoritism for super-stars and the like.
That doesn't say they don't happen, it simply says they are very difficult to study objectively. I agree that the league's blanket denial of what they did study is tough to accept.
WWM
Blown calls tend to even out over time. What often doesn't and wouldn't show up in a study like this is two or three quick touch fouls on a key player, which sends him to the bench and then forces him to be less aggressive when he does get back in.
Im sure you meatheads who follow this sham of a league (NBA) believe everything is honest and above board. The league is bought and controlled by organized crime. It's all rigged boys and girls. Wake up and smell the coffee. Stern is nothing more than a replica of john gotti.
The are other ways to control outcomes then refs.
Wilt Chamberalin, Kareem, and shaq all start their careers in one
city but end up LA LAKERS. On plays with Jerry west, the other Magic,
and then the Shaq and Kobe show. Coincidence?? When Shaq forced his way
out of LA the Lakers get Paul Gasol for Kwame Brown????? 30 times the
Lakers have played in the NBA finals. If you think the NBA does not
make more $$$ with the Lakers in the Finals then say the Blazers or
Kings( who can forget the 2002 or 03 series between Sac and LA game six
where lakers shot 27 free throws in 4th QTR of game they were getting
ELIMINATED in conference finals) your nuts!
JAKE ODONELL remember him. Came right out and said he threw Drexler out
of game 2 in NBA finals in 95 because he did not like him. Jake never
officiated another game and the NBA swept the whole ordeal under the
rug.
I will stick with the NFL where it does not matter who plays in SUPERBOWL everyone is watching it because the game sells itself. LA does not even have an NFL franchise???? NBA is a joke.. fair warning to all Blazer lovers U will never get passed the Lakers with this so called Blazer Dynasty we are building. Been there done that. It is the Harleem Globetrotters playing the Washington Generals...........
It is all about the money. The NBA wants the Lakers to win again, so they have given the Lakers home court advantage. The refs have controlled the game for years to obtain the required results. I will not be watching this year. I have seen enough of the bad calls, the no calls and the technical fouls given and taken away. So what happens when the technical foul is removed? Do the points from the foul shot get erased? This was done in favoritism. I will read about Howard's suspension for his seventh technical foul, giving the Lakers another advantage. The NBA wants Kobe, the rapist, to get his fourth ring. Kobe is no role model in my book. Should the refs start calling the game the same at both ends of the court basketball might be interesting to watch. Right now it is no better than wrestling.
as a laker fan, i acknowledge the truth of cpdrury's comment, i've always called this phenomenon the "invisible hand of the league." some of us say that god is a laker fan, because why wouldn't he affiliate with the classiest, most successful, most iconic franchise, but it's enough for us to know that david stern is a laker fan.
A 5% turnover advantage means one extra call every game to two games. That's only one additional call for every 20. As much as I think NBA officiating sucks, that's not likely to have much of an influence on game outcome.
And Lorca, how *exactly* did the NBA *give* the Lakers home court advantage out of favoritism? They had a better regular season record than Orlando - that's why they have home court advantage.
As the study admits, it doesn't delve into fouls, which, of course are the real determinant of referee or league bias. Turnovers are statistically insignificant. Too bad that there is no way to study fouls with any scientific credibility.
But we can rest assured that Tim Donaghy was just an isolated, rogue referee...
Let it be known that I hate the Lakers. Even living in LA for a while I couldn't like that team.
But here's reality - they have a good franchise. And Pau Gasol wasn't traded for just Kwame Brown. That trade also included a first round pick, Javaris Crittendon and Marc Gasol.
I agree with the fact that the Lakers have somehow ended up with a number of dominant big men who came from smaller markets. At the same time, if this bias really existed then what about the Knicks or the Clippers? That's a bigger market, or equal sized market - I think reality has more to do with the quality of the organization. Kobe Bryant was drafted 14th, then acquired in a trade. 13 teams had a shot at him and the 14th gave him up for Vlade Divac - and it's not like he had "Top 10 player all-time stamped on his forehead".
There's a reason Portland and LA have a heated rivalry. Both have put quality teams on the floor consistently. The Lakers have an attractive quality of tradition and LA has an attractive quality as a city that makes star players want to play there (don't forget Kareem went to school in LA).
As much as I'd like to use an NBA conspiracy theory as the excuse for the Lakers dominance, it just doesn't float. In the NBA one or two all-star players can ensure a period of dominance. When you happen to draft the right players once every 10 years - like Magic - then you're going to have success.
Portland has a great future and most of the past has been pretty damned good too.
ms. bachman... great story. are you on twitter? that sounds sketchy. but, seriously, are you?
This study doesn't prove there's no bias.
The bias is in the non-calls on star players to keep them in the game or in reputational calls like foul machines like Oden. However, the refs will say that star players looked at in slo-mo don't often comit the fouls because they are so gifted athletically anyway. And they will say Oden types deserve his reputation.
That said, its true David Stern is a full on gangster.
So
To all of you conspiracy theorists out there, could you tell me who has been the most dominant team for the past decade again? Oh that’s right, the San Antonio stinking Spurs, one of the smallest markets in the league. I’m sure the NBA must have pulled a lot of strings for those matchups.
A better study would look at the tape 4 groups (1) rookies (2) star players after they were rookies (3) small market teams in playoffs series and (4) teams with over 57 wins in playoff series.
Then evaluate each foul individually for clear blown calls, touch fouls and substantial fouls to see how biased the actual fouls were. Its not that hard to separate out the clearly blown calls with the aid of video tape of the games. I'm sure the nba would be happy to provide the tapes for this study (NOT lol, nba ganstas wouldn't do it).
For sample size in order to have valid t sample on the bell curve, you would only need about 150 random fouls. But there is no reason not to make the t sample size the entire population of fouls.
Or better, assuming NBA noncooperation on the tapes, start the study for the next year off taped games.
So, the home team gets more calls. Gee, I hope they didn't use taxpayer money to tell me that tidbit of enlightning information.
"NBA referees tend to favor home teams, teams trailing in a game and teams trailing in a playoff series. "
Have you ever watched an NBA game? Why would the fan's not suspect that.
Einstein said...."not everything that counts can be counted and not everything that can be counted, counts"
Every first year stats student would have a field day with this garbage in- garbage out study that is not a representative sample in the best case and is pure folly in the worst. Bluffstone is a great name for the PSU reviewer.
I dont think that there is any particular bias towards teams. Its just that there is so much inconsistency in how the game is called. Travelling is missed all the time and then randomely called. I remember a game this year in Portland where Oden clearly pinned the ball on the glass...no goaltending. It was in portland favor but c'mon...How do they miss that?
The league comes off as a joke due to this. Don't give me the line either of "its a hard game to officiate...The players are soo fast, etc."
We can put people on the moon and do heart transplants. Please dont tell me consistent officiating is unobtainable.
FactorX
The lakers are show time. Movie stars Glitz etc. When the NFL lost the LA Rams it did not change popularity or revenue at all. Take the Lakers from the NBA they are TOAST. The League lost their A$$ when San Antonio made the finals over Lakers. It is just a huge disadvantage. Almost like Oregon and OSU competing with USC for the Best athletes : FREE AGENTS??? Even Other GM"s commented on Paul Gasol deal. IT REAKED. Lakers will always get best free agents and players because of oppertunity to make more $$$ in HOLLYWOOD. Shaq even was quoted as saying that when he left Orlando. In the NFL U can play in GB Wisc and if you are good Hollywood will find U.... NFL the GAME SELLS ITSELF and does not need LA MARKET. The NBA needs LAKERS BIG TIME to get top revenue. Come on dude 30 times is what 50%? That means the Lakers have won the western conf. as much as rest of the teams combined???? And these REFS know if Lakers are in finals: REVENUE goes up... So when it is time to get new Contract officials know they will make more $$$......$$$$$$.........$$$$$$.....$$$$$$.... Can not wait till the NFL season starts..........
Are they kidding with this? David Stern and Co. must have his head stuck in a place that is dark and smelly. The NBA has the worst image problem of the major sports, not so much any more the rap hip hop thing, but the competitive balance and integrity of the game issues. We all in the past have seen referees with agendas vs teams and players, and we have seen refs that have favoritism towards players. When referees constantly and consistently call things to prevent stars from fouling out of games, or in a stars favor it no longer a matter if it is accidental or coincidental but becomes about how much of it is league directed. What sport other than basketball has a difference in how the last 2 minutes if a game are called than in the first 46? Some of the non calls are so blatant at regular speed, that those that claim its too hard to referee a NBA game need to just be quiet about it.
Oh yeah.....and they favor the Houston Rockets too. Can't let a young team get calls.
The home call advantage is obvious.
But the turnovers are not the game changers.
The game changers are charge/blocking calls and call/no call on body contact during jump shots.
In any close game, the refs decide the outcome.
the best a fan can hope for, is the calls to equalize between teams, so the better team wins.
Hello factorx! The Lakers were given home court advantage because Cleveland lost to Orlando, which was an orchestrated move. Had Cleveland won, Cleveland would have had home court advantage. Big money controls the NBA, which controls the refs. One or two blown calls in a game will change the outcome. That is why the NFL has instant replay. How many elbows has Kobe thrown in his career? Kobe is just a bum with a poor attitude, not a role model.
How about the announcers? How many times have you heard them say, "Bad Call"?????
I used to be HUGE NBA fan until I realized that what I was watching was insulting. I do agree with the article in that it seems the refs are seduced with pleasing the crowds. Some of the refs calls are blatantly ridiculous and I don't understand why more basketball fans aren't in an uproar? Watch a college game versus a NBA game to see the difference. The refs at the collegiate level seem to have more poise and let the game play out. I wish the NBA had the same officiating as the collegiate level. Maybe one day but until then I'm boycotting.
I refed high school basketball for many years. The great thing about
it is that I didn't see favoritism. We would show up to call a game in
which the players aren't even known to us, especially at the frosh and
jv games.
The only bad thing is that many officials talked only about what are
called mechanics(how to stand,point,run)but rarely talked about the
only thing the kids care about,getting the calls right.
John Grants Pass
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