The all time National League record for losses in a season was set in 1899 by the Cleveland Spiders whose record was 20-134. The modern day record was set in 1962 by the New York Mets at 40-120.
Finishing 6th in the National League Central division of Major League Baseball (MLB), the Pittsburgh Pirates recorded a 2010 regular season record of 57 wins and 105 losses.
16 by the Detroit lions in 2008-2009 NFL season
The 1899 Cleveland Spiders of the National League hold the Major League Baseball (MLB) record for worst regular season record (of all eras) with a record of 20-134, giving them a winning percentage of .130. In 1899, the Cleveland Spiders also set major league records for most consecutive losses in a season (24, from July 26 to September 16), most losses in a month (27 in July), and had 6 double-digit losing streaks. They lost 40 of their last 41 games.
1962 was the first year for the New York Mets, the National League expansion team that Major League Baseball created to replace the Giants and Dodgers that had moved to California. In 1962, the Mets, led by manager Casey Stengel, had a record of 40-120, an all time record for futility. By the way, the Houston Colt '45s, later re-named the Astros, also joined the National League that year as the other expansion team. Their record was 64-96 and finished 8th in the 10 team league, ahead of the Chicago Cubs and the Mets.
The Giants surprised most observers by posting a record of 88 wins and 74 losses. They finished third in the National League West and competed for a wild card slot for most of the season.
That would be the 1899 Cleveland Spiders (National League) whose record was 20-134.
The Seattle Mariners posted their best record in 2001. They finished the season with 116 wins and 46 losses. They set the American League record and also tied a Major League record for most wins during a 162-game season.
The Baltimore Orioles hold the American League record for most consecutive losses. The ballclub lost its first 21 games of the 1988 season. The 1961 Philadelphia Phillies set the modern major league record with 23 straight losses.
Barry Bonds hit 73 home runs for the San Francisco Giants in the 2001 season, a Major League and National League record. The American League record is held by the New York Yankees' Roger Maris, who hit 61 in the 1961 season.
18 conseutive losses in 2006-2007 season
In the major leagues there were 1618 games of baseball played in the regular season. Four American League teams (Boston Red Sox, Los Angeles Angels, Minnesota Twins and New York Yankees) played 161 games each, while the remaining six American League teams and all ten National League teams played 162 games each. New York Yankees had the best American League record with 104 wins and 57 losses, and went on to win the American League pennant. Los Angeles Dodgers had the best National League record with 99 wins and 63 losses, and went on to win both the National League pennant and the World Series.
The Giants won the National League West title with a 92-70 regular-season record. They then defeated the Atlanta Braves in a National League Division Series three games to one. In the National League Championship Series, they won the National League pennat over the Philadelphia Phillies four games to two.