Do NBA referees have a significant impact on how the games are played?

In our everlasting quest to gain some edge over either the bookmakers or the public bettors, today we’ll take a look at the NBA referees and their impact on the outcome of the games. The league has been very serious about their referees association and the people who get selected to do the hard work have to be in pristine physical condition and resistant to outside pressures, whether from the betting industry, the media or personal preference. Still, when Tim Donaghy scandal leaked out in 2007, the crystal glass was broken and the NBA referees were human again.

The league have done more to protect its own image than to make everything transparent, overprotecting the whistle blowers, but that’s another story. All that public can hear are some league statements on what should have been done in the last couple of minutes of certain games, just to please the restless spirits. Other than that, we don’t have much insight in the performance of referees during the NBA season. This is unlikely to change, so we have to accept to work with the limited data that is available.

NBA Referees characters

Some players don’t like certain referees as they can’t find the same language with them, but some referees also don’t like some players as well. You can find evidence in how quick they might lose their patience and hit them with a technical or by the steel faces when they talk to some players. It’s perfectly natural – some humans mesh better than others, both personally and professionally.

And when you are in the business for a decade or more, like some of the NBA officials are, you develop habits and interpret the rules slightly different. It’s part of the ref’s character and while the best of them won’t allow that to become a significant factor, the players surely know or sense their tendencies and will use them to their advantage.

In addition to that, the league and the referee association like to keep teams and their players informed on how some situations will be called. They occasionally send memos that contain detailed explanations why and when some calls will be made or not. It’s a welcomed thing around the league as the teams can prepare for it, but it also means that the referees are instructed how to behave in certain situations. If the league believe they need to issue such instructions, it’s only because the refs are not making the same calls that need to be universal. Imagine how many trainings and memos the referees get.

Of course, these instructions can have great influence on a NBA season, so you should always take a minute to think about what it might mean for your future wagers. The focus on the game elements from such memorandums tends to fade in a month or two, but it’s best to be prepared. It’s also worth noting that the calls that lead to more points stick longer than the ‘unpopular’ ones like travelling.

But back to the refs, it’s clear that they are not robots and that each might have his own habits or styles on how they call games. There are three of them on the court and they will often approach each other in doubt to get the correct call, and I’m not doubting their intent. Yet, the fair question arises – is the ref assignment for the game something you should account for when handicapping it? Can this selection significantly impact the game outcome?

ATS and O/U Stats

To answer these questions, let’s dig into the ref data that is available, and that’s the seasonal against the spread and over/under statistics. Keep in mind that this is not the best indicator of a ref’s impact on a game as they are not the ones playing and their statistics might be a simple consequence on a certain way they might have been assigned to the games they called.

During the freshly ended 2016/17 season, 68 different referees have officiated NBA games. Three of them called only 4 games, while a group of five refs were selected to call anywhere from 17 to 37 games. The rest of them have called more, giving us more confidence in the results due to a bit larger sample.

As far as the spread betting is concerned, quite a few refs have notably had unbalanced ATS record. The most important factor we look at is that how much of a home advantage do they give to the game hosts. The home teams have been average against the spread this season overall, covering in 49.1 percent of the time. However, there were some NBA referees that have been big homers this season. Here’s the table of the best home ATS scores per referee:

This kind of difference can raise eyebrows, especially since each of these NBA referees have officiated game in which the home team had at least 3 points winning margin, some as high as 5.5 points.

But before you write these names down for future use, let’s take a look if the previous seasons have shown similar results for the 7 referees above.

While Cutler, Kirkland and Kogut have had positive ATS for the home teams in all three seasons, it’s obvious that there’s a lot of noise to make anything of these results. Spooner, who provided +18 this season was among the worst refs for home teams judging by the frequency of their covers. Others have had up and down numbers too.

Additionally, there are 7 refs that had equally large away ‘bias’ during last season. The experience of the judges also doesn’t play any factor as the numbers for the esteemed, leading NBA refs jump up and down as much as for the greenhorns.

What is true, is that all the NBA referees will follow the current. If calling three free throws for faked shot attempt is becoming standard, than every ref is going to call it. This behavior has much larger influence on the game flow and the game esthetics than the outcome, except for the total points. The overs and unders can fluctuate largely on how the games are called.

For years now, the NBA referees are protecting the offense and it has resulted in a great uptick in points scores, which has resulted in so many records being broken or tied recently. It’s a technique that has a clear goal – attracting more fans and keeping them happy. If it changes, we’ll be notified – just keep an eye on those rules changed and league memos.

But even if the changes come, the NBA referees will act in unison. Sure, they make mistakes that can be frustrating, and if you placed a wager on a game that has been decided on how a ref called that particular game, you’ll surely spot it. But as far as the pre-game handicapping is concerned, there’s no need to worry on who has been assigned to the game. Unless it’s …. (nah, just messing with you).