The Vegas Golden Knights are one of the most unlikely success stories in recent sports history. When the most recent NHL season started, they were 250-1 odds to win the Western Conference and 500-1 to win the Stanley Cup, according to the Westgate Las Vegas SuperBook.
Other recent long shots
In their league's most-recent seasons, 12 teams in the NHL, NFL, MLB and NBA began play with 500-1 or longer odds to win their respective championships. Only two even made the playoffs (Vegas and the Indiana Pacers), and only Vegas won a playoff series.
In the NFL, the New York Jets were 1,000-to-1 odds to win a title at the start of the 2017 season. No other team was longer than 200-to-1. The Jets went 5-11 and finished last in the AFC East.
The Chicago White Sox and San Diego Padres were both 500-to-1 to win the World Series at the start of the 2017 season. They finished a combined 48 games below .500.
In the NBA, while the Pacers made this season's playoffs as a 500-to-1 title long shot, the other eight teams that were 500-1 or worse at the start of the year all went at least 24 games below .500.
In college basketball, both the UCLA Bruins and Arizona State Sun Devils were among the teams at 500-to-1 to win the NCAA tournament after Selection Sunday. Both were eliminated in the First Four.
At the 2018 Masters, 19-year old amateur Joaquin Niemann and 60-year old former champion Bernhard Langer were both 500-to-1 to win the tournament. Niemann failed to make the cut. Langer finished 18 strokes off the lead.
Other successful long shots
The Golden Knights would not be the first long shot to pay off with a championship. In 2016, Leicester City had perhaps the most surprising championship in Premier League history, overcoming 5,000-1 odds to win its first ever Premier League title. Soccer also featured another massive upset in 2004 when Greece won Euro 2004 as 150-to-1 outsiders.
The 1999 St. Louis Rams dropped to 300-1 to win the Super Bowl following an injury to quarterback Trent Green. However, backup Kurt Warner was a revelation as he led the Rams to a Super Bowl victory.
The Minnesota Twins are responsible for two of the most surprising World Series wins ever. In 1987, the Twins won it all as 500-to-1 long shots in Tom Kelly's first season as manager. Four years later, the Twins did it again, this time as 300-to-1 underdogs.
The 2015 U.S. Open was won by Flavia Pennetta, who opened at 150-to-1 to win the event. She was actually favored in the championship match over Roberta Vinci, who wasn't even offered odds in many sportsbooks prior to the start of the tournament.
In golf, perhaps the most surprising winner of The Open Championship was Ben Curtis in 2003, who entered the event with 300-1 odds. He had never even finished in the top 10 on the PGA TOUR prior to taking home the Claret Jug.