How The NBA Is Rigged

Reffing, reffing, reffing; the bane of every NBA fan in existence. Reffing in basketball is far more important than any other major sport because there are far more fouls called in an average game of basketball than any other sport. Sadly, the only thing worse than NBA refs is the discourse about NBA refs.

The Fans

Fan(atics) frequently claim the refs cost their team the game. Unfortunately, it is almost impossible to evaluate refs based on isolated incidents. Depending on the year and reffing crew, there are on average between 40-50 fouls called per game in addition to likely a similar amount of non-calls. Fans like to point to specific bad calls as their evidence and despite bad calls existing in abundance, it is proof of nothing. Fouls are frequently ambiguous and could be called either way (i.e. charge vs. block), it does not incorporate the timing of the foul in the game (i.e. giving three fouls to a big early in the game), the calls missed, the aggressive style a team is playing with and most importantly, that bad calls are part of the game and happen for both teams.

Ask fans of opposing teams to evaluate the infractions of the same game and they will give you radically different results. Similar to the effects seen with the hostile media bias, fans are much more prone to believe the other team committed a foul than their team. This is followed by the fact that every time a bad call is made against their team, they remember it vividly while in contrast, when a bad call is made against the opponent, they will likely forget about it.  This is the first fallacy; the reasons why fans frequently think the refs are against them.

Fallacy two is what I call the coulda-won-its. I am still unsure if it is a good trait or not but many people feel that it is beneath them to blame the refs for their teams loss. The often-repeated phrase is “they had a chance to win and they blew it”. The winner of a basketball game is the team that scores more points. As the refs cannot score points for one of the teams or ensure that another team misses every shot, every team regardless of the refs have a chance to win a game. The two most common examples are when a team suffers through bad reffing while also playing poorly and when a team that suffers through bad reffing has a chance to win the game but misses a last second shot.

Refs (even if they are trying to point shave) do not and cannot dictate the outcome of a game; they can only influence it. Although reffing should be neutral, bad reffing might only alter the winning probabilities of a game between 1-5%. That means that if a team should have won 100-99, bad reffing might have changed the score to 98-99 causing the team to lose. In this instance, a team might have played poorly, or missed a last second shot or had any number of other opportunities to win the game but the point still remains; they should have won the game if not for referee bias.

Is The NBA Rigged?

After attending the heartbreaking defeat of the Toronto Raptors in game 7, I could not deal with the conspiratorial talk about refs anymore. It was not the annoyance of hearing fans cite Tim Donaghy or telling me the NBA was rigged but the fact that I had no possible answers or ability to analyze the situation whatsoever. As a result, I decided I would not have an opinion about NBA refs in any capacity until I did enough research about the subject to have a grounded opinion based on something other than fan conjecture.

Although many fans like to suggest that the NBA is intentionally rigging the league, this is not something that can be substantiated. First of all, there is no evidence to suggest anything of this light. In practical terms, no league is going to bluntly tell the refs to rig a game; the effects would be far too noticeable and the consequences would be far too damaging.

The most common example cited is how the league is out to get owners like Mark Cuban or how Joey Crawford is out to get Tim Duncan. Comprehensive studies have done on both examples only to find that there is zero demonstrable bias found in both of these situations. As much as fans want to believe it, the NBA is not picking winners and instructing refs to call certain games to get revenge on someone.

That being said, I do believe that the NBA is rigged to some extent.

In 2007, economists Justin Wolfers and Joseph Price released a study indicating that NBA refs had a bias towards players of their own race. They discovered that players scored 2.5% more points and have 4% fewer fouls called when the reffing crew shares the same race as them. The NBA immediately rejected this assertion and claimed that not only is there no racism in the NBA but that NBA refs were the most scrutinized and monitored group of employees in the world.

The NBA followed this up with an internal study “proving” that there was no racial bias in the NBA.  Unfortunately, the study was never publically released but it was shared with a number of academics. Upon inspection, the NBA’s study contained a flawed methodology but even still, it actually confirmed the Wolfers-Price thesis.  Seven years later, Wolfers and Price did their study again with new data and found that magically, the bias had completely disappeared. Although the NBA claims to have done nothing differently, they were able to mitigate the racial bias of referees completely. The truth of the matter is that NBA refs were never intentionally being racist, but had a sub-conscious bias. When confronted with the bias and forced to think about, they corrected it and started calling the game more objectively and less partially.

This is why I think the NBA can be described as being rigged. There are a number of biases that impact how officials call basketball games, which make it more likely for certain teams and players to excel. These biases have been studied and likely could be mitigated but it appears as if nothing has been done to confront them. Although not all of it may be solvable, I believe the NBA has intentionally allowed these issues to persist because the league benefit from their consequences; rigging my omission. There is evidence to suggest that referee biases exist to make games more competitive, to extend playoff series, to favour superstars and large market teams; most importantly all of these biases provide financially desirable results for the NBA.

Here are some examples that have been discovered.

In regards loose ball fouls in plays between a star player and a non-star player, the non-star player will get called for a foul over 57% of the time. However, if the star player is in foul trouble, the chances that the non-star will be called for the foul increases to over 73%.

Fouls can be distinguished between two groups, discretionary and non-discretionary calls. For example, a 24 second shot clock violation or an out of bounds is a non-discretionary call. The ref has no choice, its black and white and has to be called. Then there are things like hyper-discretionary fouls such as travelling, where the visiting team has a 15% higher chance of being called for one.

Home teams have more than an 11% advantage in discretionary fouls while only a 3% increase in non-discretionary fouls.  In the fourth quarter, the discretionary fouls called in favour of the home team reduces to 8% indicating that the refs like to take themselves out of the game in the fourth quarter. Meanwhile non-discretionary foul differences reduce from 3% to almost 0% in the fourth quarter.

In the playoffs, the amount of discretionary fouls called in favour of the home team increases to over 12% making the effect even more pronounced. Similarly, when the home team is facing elimination in the playoffs, they were called for 4.1 fewer fouls per game until game 7 (with no distinction in non-discretionary fouls) where this number switched to only 1 less foul called per game. For both home and away teams, when facing elimination, teams receive .35 fewer discretionary fouls called.

When a team is losing by a large margin, their discretionary fouls decrease by over 15% while those down between 4-10 points have only a 3.7% advantage in discretionary fouls. Moreover, teams winning by between 4-10 points have 11% more discretionary fouls.

Studies also found that the market size of a team has a statistically significant correlation with a team’s likelihood of winning when factoring in the teams seeding. For example, the New York Knicks were found to have an equivalent to a 3.5 point advantage per game when they played the Indiana Pacers just based on their market size. In comparison, a team had a 1.55 point advantage for every increase in seeding. The evidence indicated that the bias equaled a 0.021 point increase for every 100,000 person discrepancy in the market size between two teams.

None of these biases guarantee any results or ensure only the Lakers will win. However, these biases certainly can and do impact the final results of games making certain outcomes more likely to happen.

There is no evidence to suggest that the refs do any of this intentionally or even if the NBA is selecting certain refs to compound these effects. The only evidence to suggest something along these lines is that there is a strong correlation between the refs selected to officiate game 7’s and those selected to officiate games between strong visiting teams playing weak teams at home in the regular season. As these games would benefit from a higher level of a home team bias, this provides some evidence into the idea of the NBA having a tacit acknowledgement of the idea of “company men” who ensure the profitable bias for the NBA are in effect.

That being said, the far more likely explanation is that like all individuals, referees suffer from cognitive biases. When teams play at home, the fans influence them. Superstars are perceived as being better basketball players they trust more, so they would get more calls. When a team is losing badly, the fouls are less important for the winning team so the refs likely have an easier time calling fouls on them. Similarly, in the fourth quarter or a game 7, the refs do not want to be the one’s taking the heat for any bad calls so they would try and distance themselves from the game. Large market teams for the most part have stronger basketball histories and more favourable press coverage likely leading to some sort of halo effect where the refs subconsciously view them as being the better team and less likely to make calls against them.

In baseball, the advent of computer tracking systems for balls and made umpires across the board 25% more consistent and has increased the percentage of pitches umpires call correctly. Similar to NBA refs and racism, it was not that the umpires were intentionally blowing calls before but that just by being aware of where their biases were (which are obvious in the MLB) and confronting them, it becomes possible overcome one’s heuristic.

The NBA is not an organization of franchises competing with one another, but an organization to increase the value of each team. NBA franchises do not derive value from being better at basketball, but merely by being a part of the NBA. If the Harlem Globetrotters signed elite NBA talent, they would still nowhere near as valuable as the Milwaukee Bucks (worth 550 million dollars) simply for the fact that the Bucks are part of the NBA.

As all of these biases improve the financial health of the league and therefore increase each franchise’s individual value, it is entirely possible that the franchises have minimal incentive to do anything about it. A similar example can be seen with the concept of parity. If the NBA were to abolish maximum contracts in the NBA, the league would almost instantly become more equal and have more parity. Owners have not made a push for this because despite their team possible having a lower chance at winning, their team’s value might decrease because of the benefits the league receives by having super-teams winning championships.