From the New Yorker’s Brett Surowiecki.  Originally published April 16, 2016:

 

When the New York Islanders take the ice on Wednesday night for the first game of their second-round playoff series against the Tampa Bay Lightning, they can be grateful to their captain, John Tavares, who scored both goals in their series-clinching, double-overtime comeback win against the Florida Panthers on Sunday. But the Islanders have someone else to thank, too: the officials at that Panther game. Tavares’s performance that night was exceptional—he tied the game, with fifty-four seconds to go in the third period, and then scored a beautiful wraparound goal in overtime—but he was only in position to become a hero because of what Sporting News termed “the worst non-call of the playoffs.” Just before he scored the game-tying goal, the Panthers had the puck in the Islanders’ defensive zone with the net empty (the Islanders had pulled their goalie in favor of an extra forward). As Florida’s Vincent Trocheck went to shoot, the Islanders’ Matt Martin, diving to knock the puck away, tripped Trocheck, who fell to the ice. Trocheck lost the puck, and the Islanders eventually retrieved it, leading to a rush that culminated in Tavares’s goal.

The moment the trip happened, it was obvious to anyone watching that it was an infraction. It was also obvious, to most hockey fans, that there was little chance the officials would send Martin to the penalty box. Doing so would have required them to override two powerful biases that shape sports refereeing: hesitancy to call penalties in important games, and favoritism toward home teams. Officiating has already been the subject of much discussion in this year’s playoffs, since this is the first season that the National Hockey League has allowed coaches to challenge offside and goaltender-interference rulings. The Islanders game showed, though, that even in an era when sports leagues are dedicated to using instant-replay technology to make sure that calls are correct, long-established biases continue to have an outsized impact on games.

 

The tendency for N.H.L. refs to avoid assessing penalties in deciding playoff games is well documented. As Nate Silver showed in a 2014 piece for FiveThirtyEight, since the 1987–88 season the total number of penalty minutes served in Game Sevens is roughly half of what it is during the rest of the playoffs and the regular season. This isn’t, as far as anyone can tell, because teams play differently when series are on the line. It’s that referees, anxious not to determine the outcome of big games, let infractions they would otherwise call go unpunished. As Greg Wyshynski, of Yahoo Sports, put it after the Islanders game, “The zebras don’t want to decide it.” This effect is most pronounced in rubber matches, but it’s widely believed to play out anytime a series might be decided.

Beyond referee timidity, another, arguably more important, factor helped the Islanders: the game was being played at Barclays Center, in Brooklyn, which meant that calling a penalty would have required a referee to inflame sixteen thousand screaming Islanders fans. Officials may like to believe that their judgments are unaffected by crowds, but the evidence shows, overwhelmingly, that refs are tougher on away teams and more lenient with home teams. This is true of every major sport that researchers have looked at, whether they’re assessing penalty shots in European soccer, balls and strikes in baseball, or penalties in the National Football League.

The N.H.L. is no exception to this rule. A study of every game played in the 2007–08 season, for instance, found that away teams received ten per cent more penalties than home teams did. And in the 2011 book “Scorecasting,” L. Jon Wertheim and Tobias Moskowitz write that, on average, the home-team bias in hockey officiating, which leads officials to give home teams more time on the power play, is worth .25 goals per game. Indeed, the authors argue that home-ice advantage in the N.H.L.—where home teams win about fifty-six per cent of all games—is almost entirely due to biased officiating.

 

 

Home-team bias occurs for a number of fairly intuitive reasons. In judging whether an action is severe enough to warrant a penalty, refs may, for instance, take cues from the spectators’ reaction. They are also subject to the very human desire to go along with the crowd. A 2007 study of refereeing in Italian soccer games confirmed the outsized influence fans have on officials. At matches that were played in front of empty stadiums, because fans had been banned owing to hooliganism, the researchers found that referees’ tendency to punish away-team players far more harshly than home-team players vanished. In fact, when the stadiums were empty, home teams were called for more fouls and yellow and red cards than away teams were—clear evidence, as the researchers put it, “that social pressure from the spectators affects the referees’ behavior.”

If sports leagues are serious about improving officiating standards in order to make matches fairer, then it isn’t enough to insure that the occasional blown call is fixed. They will need to find new ways to counteract deeper biases in the way refs call games. Expanding the use of instant replay could help in this regard (despite complaints that it interrupts the flow of play); as Wertheim and Moskowitz point out, when the N.F.L. brought the coach’s challenge into the game the home-town advantage declined. N.H.L. officiating might also improve if the league sends a clear message that a penalty is a penalty, regardless of when, or in what arena, it happens. To accomplish this, it could, for instance, adopt the approach that the National Basketball Association has taken in recent years, acknowledging when consequential refereeing mistakes, including uncalled infractions, have taken place.

Some hockey observers would no doubt decry that approach, on the ground that officials are in fact right not to call penalties like Martin’s trip of Trocheck. But their underlying argument, that the zebras shouldn’t decide the games, would miss an obvious point: the penalties that referees don’t call are as capable of deciding games as the ones that they do.