NHL referees are far from perfect, and there have been multiple moments when a referee's decision impacted a game's outcome. Referees do have a tough job, but there are some calls you just need to get right.
Here are the 10 most controversial calls in NHL history, and their impact on NHL history.
Although this call didn't mean anything in the grand scheme of things, it could have prevented the Chicago Blackhawks from winning the Stanley Cup.
Niklas Hjalmarsson appeared to have scored a game-winning goal for the Blackhawks, but a whistle away from the play caused the goal to be disallowed.
Although the scrum involving two players had nothing to do with the events occurring down the ice, referee Stephen Walkom decided to call matching minors on Kyle Quincey and Brandon Saad. It is OK to look at this moment in hindsight and laugh, but can you imagine what would have happened if the Red Wings scored in overtime?
This clip is a popular highlight on most hockey blooper reels, and it deserves another mention. The Chicago Blackhawks and Winnipeg Jets were tied and they headed to overtime, and then this happened.
During the overtime period, goaltender Ed Belfour was trying to clear the puck, and a Winnipeg Jet player intercepted it before gloving it into the net.
The referees strangely awarded the Jets a goal and victory, and the play is still controversial and comical to this day.
During this year's playoffs, the San Jose Sharks were very lethal on the power play. In an elimination Game 4, the referees awarded the Sharks a power play after Daniel Sedin was controversially called for boarding.
The Sharks would only need seconds to score, and they effectively eliminated the Canucks in a four-game sweep. Replays show that Sedin's hit was a hockey play, and momentum naturally sent Tommy Wingels into the boards.
It was a very controversial call at the time, and history will look back on this moment as one that played a role in Alain Vigneault's dismissal as head coach of the Vancouver Canucks.
During the playoffs back in 2000, the Buffalo Sabres were cheated when John Leclair scored an "illegal" goal. He shot the puck so hard that it went through the side of the net, but it counted.
The Flyers would go on to win the series, but it would be interesting to see what would have happened if this goal never counted.
There have been a number of calls in which "intent to blow" has played a role, but in this incident the referee blew the whistle. The referee had lost sight of the puck and blew the whistle because it appeared that goaltender Justin Peters had made a save.
Sometime after the whistle blew, the puck ended up in the back of the net, and the officials decided to review it. After some discussion a goal was mysteriously awarded, even though the play had been waived dead on the ice.
Whenever there is a ruckus in front of the net before a goal is scored, referees usually wanted to get together to make sure no shenanigans took place. However, during this playoff game it appears that Joel Otto kicked the puck into the net when he spun towards the net.
The goal in question was not clean by any means, and it had some further implications. The Flames would go on to win the Stanley Cup, but what would have happened if this goal did not count?
During the 2012 Stanley Cup Final, Rob Scuderi turned his back on Steve Bernier and was hit into the boards. Bernier was ejected from the game, and the Los Angeles Kings received a five-minute power-play.
The Kings went on to score three power-play goals, and they won the Stanley Cup because of it. There was a ton of controversy about the hit at the time, and NBC's Pro Hockey Talk aggregated the differing opinions of the controversial call at the time.
This call was deemed controversial, because moments before Bernier's hit, Jarrett Stoll took down Stephen Gionta with a similar play.
In 2004 the Tampa Bay Lightning and Calgary Flames met in the Stanley Cup Final, and the Flames had a prime chance to win the Stanley Cup. A non-goal call robbed them of this, and the Lightning went on to win the Cup in seven games.
Martin Gelinas appeared to score a goal, and instead of reviewing the play, referees decided to continue play. The most controversial part of this incident is not whether the puck was in, but the fact that the NHL did not review it in a Stanley Cup elimination game.
Wayne Gretzky played a critical role in the elimination of the Toronto Maple Leafs from the playoffs when he scored a very controversial goal. The goal is controversial because of events that preceded it. Referees got together for a caucus after it was seen that Doug Gilmour was high sticked by Gretzky.
After a discussion it was deemed that no penalty would be called, and Gretzky stayed on the ice even though Gilmour was profusely bleeding. Had Gretzky been penalized, he wouldn't have had a chance to score, and the Maple Leafs would have had a chance to advance to the Stanley Cup Final.
This is the most controversial call in NHL history, because the Dallas Stars won a Stanley Cup as a result.
Throughout the entire season the NHL had cracked down on players scoring from the crease area, but they turned a blind eye as Brett Hull tapped a game-winning goal home with his skate parked inside the crease.
To this day it is a moment of infamy for Buffalo Sabres fans, because they arguably were cheated in the biggest way possible.