Playoff pressure. Players feel it. Coaches try to control it. Fans freak out over it. And according to a recent study, referees can crack under it.
Michael Lopez, a doctoral student in biostatistics at Brown University, and Kevin Snyder, an assistant professor of sport management at Southern New Hampshire University, assessed the frequency of even-up calls in their paper, “Biased Impartiality among National Hockey League Referees,” published in the International Journal of Sport Finance. Lopez and Snyder found that referees exhibit what they call “biased impartiality.” Meaning, referees subconsciously try to make games as balanced as possible to achieve a perception of fairness.
Nothing nefarious there. The problem is referees may make even-up calls that unfairly balance the number of penalties between teams, and this can actually affect who wins. So despite their best attempts otherwise, refs often have a huge impact on playoff games.
Lopez, a diehard Boston fan, got the idea for the study while watching the fifth game of the 2011 Stanley Cup final. His Bruins were tied with the Canucks 2-2 in the series and early in Game 5 the B’s had their chances to win. Vancouver was called for three straight penalties in the first, and after offsetting minors to Milan Lucic and Alex Burrows late in the period, the Canucks got another penalty early in the second. Sure enough, the penalty pendulum swung the other way. Boston was called for three straight minors and didn’t get another power play the rest of the game, losing 1-0.
“We had our chances and now we’re not going to get the calls,” Lopez said. “We didn’t get the calls, and I finally just thought to myself, ‘Well, what if I just measured this?’ ”
Lopez and Snyder crunched the numbers for all playoff games between 2006 and 2012. They found that the likelihood of even-up calls grew as the pressure situations for referees increased. Teams with a higher number of first-period penalties were 75 percent more likely to have fewer second-period penalties than their opponent. This difference was higher for home teams (which were 140 percent more likely to have fewer second-period penalties) and teams in the Stanley Cup final (150 percent), with the largest difference found among teams in a Game 7 (about 10 times as likely to receive even-up calls). Third-period numbers showed similar relationships. What’s more, it didn’t matter what the score was.
“That’s an important point, because obviously the thought would be if you’re playing with the lead, you’re going to be playing differently, which is going to impact the number of penalties you have,” Lopez said. “But the results we found were that the number of penalties you have is independent of the score entering the period…Whether you were ahead a goal or behind a goal, it didn’t seem to have an impact on the number of penalties.”
The upshot of all this is that referees’ bias toward balance can end up favoring one team. Lopez and Snyder found that in playoff games tied at the end of the first period, the team with more penalties was about 15 percent more likely to win than the team with fewer penalties, perhaps due to the even-up calls it is likely to receive later on. Among teams with a higher number of first- and second-period penalties, it was 10 percent, for tie games heading into the third period.
The NHL didn’t respond to a request for an interview.
The study doesn’t suggest referees are doing anything malicious or conspiratorial. Lopez and Snyder are just pointing out how playoff pressure subconsciously affects how refs call a game. To their credit, referees are just trying to “let the players decide the game,” as the old adage goes. To do that, they need to be fair, and to be fair they feel they have to be balanced by calling penalties as evenly as possible. Retired ref Kerry Fraser officiated almost 2,000 regular season and more than 250 playoffs games. He knows well the pressures officials face in the post-season.
“Any referee that would not admit to making a judgment that would be deemed to be an even-up call would not be honest,” he said. “Each referee wants to think that he’s bigger than making an even-up call, but we’ve all done it because of that need to be fair and balanced. So the fair element of it may, at times, create the need to balance things out, for sure.”