Top 5 biggest MLB second-half collapses of the 21st century

There are 162 games in an MLB season. It would be an understatement to say every game counts. Only about one-third of the teams will make the trip to the playoffs. It is of utmost importance that each team shows not only dominance, but consistency as well.

Many teams dominated the early stages of the MLB season. However, as the saying goes, "It's not how you start; it's how you finish." Let's take a look back at the five most disastrous second-half collapses in modern-day MLB.

#5 2005 Cleveland Indians

The then Cleveland Indians were just 2.5 games back in the American League Central race and owned a 1.5 game lead in for the Wild Card spot. The Indians had won nine of their last 10 games before being overcome by the bottom-dwelling Kansas City Royals and Tampa Bay Devil Rays.

They had a chance to salvage their MLB season when they finally faced the Chicago White Sox. However, the Southsiders swept them, and they missed the playoffs.

#4 2007 New York Mets

On September 12, 2007, the New York Mets were the clear favorites to clinch the National League East. They led the division by seven games before everything went haywire. They lost five games in a row, then lost six of their last seven games.

They just would not be able to escape the seven curse. During the last game of the season, their starter Tom Glavine surrendered seven earned runs to the lowly Florida Marlins. They would get beaten by the Marlins at home and miss the playoffs by just one win.

#3 2011 Atlanta Braves

In what was the most dramatic last day in recent MLB memory, the Atlanta Braves would go on to lose their playoff spot. This shouldn't have been the case, however, as they led the St. Louis Cardinals by 8.5 games on September 6.

Heading into the final week, they were still leading the Cards by three games. Their bullpen would crumble on the final day, however, as they were defeated by the Philadelphia Phillies in 13 innings. The Cards would advance to the postseason and win the World Series title that year.

#2 2009 Detroit Tigers

In one peculiar instance, the Detroit Tigers dueled with the Minnesota Twins for a one-game tiebreaker to determine which team would advance to the postseason.

Detroit held the AL Central lead for close to five months. However, inexplicable losses to the Minnesota Twins and White Sox saw them lose the lead and their spot in the postseason.

#1 2011 Boston Red Sox

Heading into September 2011, the Boston Red Sox led the AL East. By the end of it, they finished third. The other half of the most dramatic last day in recent MLB memory, the Red Sox were one out from a postseason slot but wasted their opportunity away.

Boston led the Baltimore Orioles 3-2 before coughing it up and losing 4-3 in a game that would have solidified their playoff chances. They also needed to rely on their arch rival New York Yankees to beat Tampa Bay to ensure Boston's position in the playoffs. The Bombers led the Rays 7-0 but proceeded to crumble and lose 8-7.