What's the best & worst final MLB record ever? Also, what's the best undefeated start to a season?

Question

What's the worst winless start to a season?

Answer 1

1916 Philadelphia A's have the wrost winning % for a season (.247) altho the 1962 Mets have the record for the most losses (120)

2001 Seattle Mariners have the most wins for a season (116)

Answer 2

As for best and worst MLB records it depends on what you would consider the start of Major League Baseball.
As for the best record, In 1875 the Boston Red Stockings went 71-8 for a .899 winning percentage, in the National Association. However the National Association was more a collection of semi-pro type teams with floating rosters and schedules, so most baseball do not consider it a major league, and that Major League Baseball began with the establishment of the National League in 1876.
The 1884 St. Louis Maroons in a league known as the Union Association went 94-19 for a .832 winning %. Since the Union Association only last one season, and a borderline major league, most experts do not deem this league as a major league.
In 1880 the Chicago White Stockings went 67-17 for a .796 percentage. Of course the 1880 National League, in addition to only playing 84 games, had a weak league with teams in Troy and Worchester.
For season that lasted at least 150 games, the best record is of the 1906 Chicago Cubs, who went 116-36 for a .736 mark. That team somehow lost the World Series. That team still holds the win record along with the 2001 Seattle Mariners who went 116-46, and did not even make it to the World Series.
As for worst record, in the National Association days of 1872 a team in Washington went 0-11. For a fulll season the record belongs to the infamous 1899 Cleveland Spiders who went 20-134 for a .130 winning percentage. That team had a 6.37 ERA, and commited 388 errors which were responsible for 357 unearned runs. This team was hampered by the team owners also owning the St. Louis Cardinals, so the more talented Spider players were routinely transferred to the Cardinals.
The worst post 1900 team was the 1916 Philadelphia Athletics who went 36-117 for a .235 winning %. The loss record is held by the 1962 Mets with 120, but by getting 40 wins the "Amazing Mets" managed to have a .250 winning %.
The longest losing streak to start a season was the 1988 Baltimore Orioles who lost their 1st 21 games. During the streak they fired manager Cal Ripken Sr., and decided to change the team logo and uniform at the end of that season.

Answer 3

Best winning streak from the beginning of the season:

13-0

by the

1982 Atlanta Braves

and

1987 Milwaukee Brewers


Going back to olde-tyme, 19th century ball, we find these equally impressive (if not moreso) streaks:

1874 Boston Red Stockings (National Association), 13-0 (finished 52-18)

1884 St. Louis Maroons (Union Association), 20-0 (finished 94-19)

and
1875 Boston Red Stockings (Nat'l Assoc), 26-0 (later 35-2, 50-4, 70-7, finished 71-8)

The worst start to a season was by the 1988 Baltimore Orioles, who went 0-21 and finished April at 1-22.