Team stats kept timing out on me, so the only other way I could figure to determine most wins in a season was to look at every team's "Seasons" page and sort by wins. Since I'm doing that, I'll do every teams record high wins season.
Washington Senators: 109 (1978, lost DCS)
Toronto Blue Jays (at the time, Cleveland Naps): 119 (1957, lost WS)
NY Yankees: 115 (1929, Won WS)
Detriot Tigers: 103 (twice, 2015 and 1922 (as TX Rangers), Won WS and lost DCS)
Boston Red Sox: 104 (1966, their only 100 win season, lost DCS)
Baltimore Orioles: 107 (1996, lost DCS)
Pittsburgh Pirates: 115 (Twice, 1988 (lost DCS) and 1969 (Won WS))
Philadelphia Phillies: 110 (2008, lost DCS)
NY Mets: 97 (1923, lost WS)
Louisville Colonels: 108 (2005, won WS)
Buffalo Bisons: 117 (1945 as NY Gothams, Lost DCS)
Brooklyn Robins: 111 (1904 as Chicago Cubs, Lost LCS)
Seattle Mariners: 102 (Twice, 1977 as TX Rangers (lost DCS), 1966 as KC Royals (Lost DCS))
Oakland Athletics: 115 (1945, Won WS)
Minnesota Twins: 113 (1913, lost WS)
Kansas City Royals: 119 (1904 as Seattle Pilots, Won WS)
Houston Colt 45's: 115 (1980, as Astros, Lost LCS)
Anaheim Angels: 112 (1915, as Seattle Mariners, Lost DCS)
St. Louis Cardinals: 114 (1936, Won WS)
SF Giants: 113 (1970, Won WS)
SD Padres: 116 (2026, TBD)
LA Dodgers: 103 (1947, Won WS)
Colorado Rockies: 109 (1997, Lost LCS)
Chicago Cubs: 110 (1914, lost WS)
Bookmarks