Historically, there's nothing more definite in sports than a 3-0 lead in a best of seven series. What are the odds a team blows the lead and allows the opposing team to win four consecutive games? It's never once occurred in NBA history, and the NFL doesn't have series. In fact, it's only happened five times in sports history.

The 2014 San Jose Sharks are the newest team to make history for the wrong reason. The Sharks disappoint their fans quite a bit, so their fans might be somewhat used to this. In the first round of the 2014 NHL playoffs, the Sharks took a 3-0 series lead against the Los Angeles Kings and it looked like they were heading to the second round for sure.

But somehow the Sharks found themselves running out of water against the Kings, losing four straight games. The Sharks didn't just lose four straight—they were embarrassed. In the final four games, the Kings would defeat the Sharks 6-3, 3-0, 4-1, and 5-1 in game seven. Way to go out with a fight, Sharks.

The 2010 Boston Bruins postseason is one Beantown wants to forget. In the second round of the playoffs, the Bruins faced off against the Philadelphia Flyers and took a commanding 3-0 series lead. In game four, the Bruins had a chance to sweep the Flyers but lost in overtime. After two more Flyers victories, a game seven showdown took place with the Flyers taking game seven in Boston. The city of Brotherly love would watch the Flyers skate all the way to the Stanley Cup, only to lose to the Chicago Blackhawks.

The Bruins would get the last laugh, however. The next season, they would eliminate the Flyers in the second round and win the Stanley Cup.

The 1975 Pittsburgh Penguins became the second team in NHL history to blow a 3-0 series lead against the New York Islanders. The Islanders were the better team with better players, but somehow lost three straight games. They would recover by winning three consecutive games, forcing a game seven showdown at home, but lost 1-0. What was so impressive about this Islanders squad is that in the very next round (against the Flyers) they would again find themselves down 0-3, and again they forced a game seven. Unfortunately, they couldn't repeat the magical comeback once again and lost in game seven.

The 1942 Detroit Red Wings are the only team to lose a 3-0 series lead in the Stanley Cup Finals. Against the Toronto Maple Leafs, the Red Wings looked to win their third Stanley Cup. The win seemed like a sure thing, but the Maple Leafs rallied back, winning four consecutive games. The Maple Leafs won game seven at home 3-1 in front of their excited fans. On the the bright side, the Red Wings won the Stanley Cup the very next season, so not all is bad in Hockey Town.

The 2004 New York Yankees are the only Major League Baseball team to not win a series win up 3-0. For most Yankees fans, this is the most disappointing moment of all time. The Yankees lost the American League Championship to the Boston Red Sox and the Sox would go on to win the World Series breaking the "Curse of the Bambino." In games four and five, the Yankees and Red Sox would go to extra innings with the Red Sox winning both by just three combined runs. Game seven was played in the Bronx, but the momentum carried over for a Boston 10-3 blowout victory.

It's only occurred five times in sports history, but let it be known: no series lead is safe.