<P> For example, the Chicago White Stockings won the National League's first pennant in 1876 with a 52 - 14 record (. 788), and won the 1880 NL pennant with a 67 - 17 record (. 798), which stands as the overall percentage record between the National or the American League . The White Stockings' 1880 record would project to a record of 129 - 33 under the modern schedule of 162 games, while Pythagorean expectation based on the White Stockings' results (538 runs scored, 317 runs allowed) and a 162 - game schedule would translate to a record of 120 - 42 . </P> <P> The all - time best single season record belongs to the Cincinnati Red Stockings, who posted baseball's only perfect record at 67 - 0 (57 - 0 against National Association of Base Ball Players clubs) in 1869 . Their record would stretch to 81 - 0 across the 1870 season before losing 8 - 7 in eleven innings to the Brooklyn Atlantics in Brooklyn on June 14 . </P> <P> The second - best record belongs to the 1875 Boston Red Stockings of the National Association, who finished with a record of 71 - 8 (. 899), but the status of the National Association as a major league has long been disputed . The Red Stockings record would project to 146 - 16 under the modern schedule of 162 games, while Pythagorean expectation based on the Red Stockings results (831 runs scored, 343 runs allowed) and the modern 162 - game schedule would translate to a record of 138 - 24 . </P> <P> The National Association folded at the end of 1875, and the Red Stockings, who had won the last four pennants, joined the National League for 1876, being renamed the Red Caps . The team went 39 - 31 for a fourth - place finish in 1876 before winning the 1877 and 1878 pennants with records of 42 - 18 and 41 - 19 . </P>

Who won the most games in mlb history