References are numbered in [brackets], which are listed here. A number after the dot gives the page in the source.

Last updated: 2008 June 28.

1920 January 3 New York Yankees purchase Babe Ruth from Boston Red Sox for $125,000. [1] January 4 First Black baseball league, National Negro Baseball League, organizes. [1] January 5 Boston Red Sox sell Babe Ruth to New York Yankees. [1] January 10 Montreal Canadiens (14) and Toronto Saint Patricks (7) score NHL record 21 goals. [1] January 12 Annual drafting of baseball players from minor leagues to be done in inverse order of the final standings, agreed to. [1] January 30 Québec's Joe Malone sets NHL record of 7 goals in a game. [1] January 31 Joe Malone, Québec Bulldogs, sets NHL record with 7 goals in a game against Toronto. [1] February 1 Soccer team Quick Boys forms. [1] February 9 Joint Rules Commission bans foreign substances and alterations to baseballs. [1] February 10 Baseball outlaws all pitches involving tampering with the ball. [1] February 12 National League votes 6-2 for one commissioner American League votes 6-2 to keep group commission. [1] February 13 National Negro Baseball League organized. [1] March 3 Montreal Canadiens scores NHL record 16 goals beating Québec Bulldogs. [1] March 10 NHL's Québec Bulldog Jim Malone scores six goals vs Ottawa Senators. [1] March 20 US Ladies Figure Skating Championship won by Theresa Weld. [1] US Men's Figure Skating Championship won by Sherwin Badger. [1] April 1 Stanley Cup: Ottawa Senators (NHL) beat Seattle (PCHA), three games to 2. [1] April 8 LONGA soccer team forms in Tilburg. [1] April 17 American Professional Football Association forms (NFL). [1] April 19 24th Boston Marathon won by Peter Trivoulidas of Greece in 2:29:31. [1] April 20 (to September 12) The 7th Olympic Games are held in Antwerp, Belgium. [7] Philadelphia Phillies manager Gravvy Cravath puts himself in as pinch hitter, his three-run homer and beats New York Giants 3-0. [1] May 1 Babe Ruth's first New York Yankees homerun and 50th of career, out of Polo Grounds. [1] Brooklyn Dodgers tie Boston Braves, 1-1, in 26 innings. [1] May 2 First game of National Negro Baseball League played in Indianapolis. [1] May 8 46th Kentucky Derby: Ted Rice aboard Paul Jones wins in 2:09. [1] May 14 New York Giants inform New York Yankees that the lease allowing them to play in the Polo Grounds will not be renewed at end of 1920 season. [1] Washington Senator Walter Johnson wins his 300th game vs Detroit. [1] May 15 Soccer team ADO '20 forms in Heemskerk. [1] May 17 Maitland Hathorn cricketer (325 runs in 12 Tests South Africa 1901-11), dies. [1] May 18 46th Preakness: Clarence Kummer aboard Man o' War wins in 1:51.6. [1] June 20 New York Yankees win protest of 1-0 Chicago White Sox win and game is replayed. [1] July 1 Washington Senator Walter Johnson no-hits Boston Red Sox, 1-0. [1] July 6 New York Yankees score team record 14 runs in one inning vs Senators. [1] July 15 Ruth ties his record of 29 home runs in a season. [1] July 16 Ruth sets season home run record with 30 en route to 54. [1] US wins Davis Cup sweeping Australia in five straight matches. [1] July 25 Boston Red Sox turn triple-play, but Ruth's 35th home run leads New York Yankees to 8-2 win. [1] July 27 Resolute beats Shamrock IV (England) in 14th running of America's Cup. [1] August 8 Detroit Tigers beat New York Yankees 1-0 in shortest American League game, 73 minutes. [1] August 16 Ray Chapman, of the Cleveland Indians is hit in the head by New York Yankees' Carl Mays pitch; he dies next day, only major league fatality. [1] August 17 Ray Chapman hit in the head by New York Yankees' Carl Mays pitch, dies. [1] August 20 Preliminary meeting in Akron to form American Pro Football League. [1] August 25 First US woman to win in Olympics (Ethelda Bleibtrey). [1] September 12 7th Olympic games close in Antwerp Belgium. [1] September 17 National Football League organized in Canton Ohio. [1] September 25 Vern Bradburn of Winnipeg Victorias kicks 9 singles in a game. [1] September 28 Eight Chicago White Sox indicted, threw 1919 World Series (Black Sox scandal). [1] September 29 Babe Ruth sets then home run season record at 54. [1] October 2 Cincinnati Reds beat Pittsburgh Pirates two games out of three in a tripleheader. [1] October 3 NFL (then American Pro Football Association) plays first games. [1] October 10 Indian's Bill Wambsganns makes first unassisted world series triple play (World Series #17). [1] Indian's Elmer Smith hits the first world series grand slam (World Series #17). [1] Phoenix Cardinals (then in Chicago) play first NFL game, a 0-0 tie. [1] October 12 Cleveland Indians beat Brooklyn Dodgers, five games to two in 17th World Series. [1] October 17 Chicago Bears (as Decatur Staleys) play first NFL game, win 7-0. [1] October 29 Edward Barrow named New York Yankees general manager. [1] November 12 Judge Kennesaw Mountain Landis elected first baseball commissioner. [1] November 14 American Pro Football League's Chicago Tiger Joe Guyon punts 95 yards. [1] November 25 WTAW of College Station, Texas, broadcast first football play-by-play. [1] December 4 First Pro football playoff game Buffalo-7, Canton-3 at Polo Grounds. [1] 8th Canadian Football League Grey Cup: University of Toronto defeats Toronto Argonauts, 16-3. [1] December 5 Pro football playoff game Akron and Buffalo 0-0 tie, title undecided. [1] December 14 Heavyweight Jack Dempsey knocks out Bill Brennan in 12 for heavyweight boxing title in New York City, New York. [1] December 17 American League votes to allow pitchers who used the spitball in 1920 to continue using it as long as they are inthe league (The National League will do the same - 17 holdover spitballers in all). [1] December 19 First US indoor curling rink opens (Brookline Massachusetts). [1] December 20 Bert Collins scores 104 on Test Cricket debut vs England SCG. [1] December 21 Claude Tozer cricketer (dashing New South Wales batsman), shot to death. [1] December 31 Roy Park makes first-ball duck in only Test Cricket inning, vs England at Melbourne Cricket Ground. [1] 1921 January 12 Kenesaw Mountain Landis becomes first commissioner of baseball. [1] January 26 Soccer team GVAV of Groningen Netherlands forms. [1] Toronto Saint Pat Corb Denneny scores six goals vs Hamilton Tigers. [1] January 29 Billy Gunn cricket (score 392 runs for England including a century), dies. [1] February 5 New York Yankees purchase 20 acres in the Bronx for Yankee Stadium. [1] February 12 Charles Leslie cricketer (4 Tests England vs Australia 1882-83), dies. [1] February 15 Arthur Mailey completes 9-121 vs England, Australian Test Cricket record. [1] February 27 Schofield Haigh cricketer (England all-rounder 11 Tests 1898-1912), dies. [1] US female Figure Skating championship won by Theresa Weld Blanchard. [1] US male Figure Skating championship won by Sherwin Badger. [1] March 1 Australia Cricket team complete 5-0 drubbing of England. [1] April 4 Stanley Cup: Ottawa Senators (NHL) beat Vancouver Millionaires (PCHA), three games to 2. [1] April 11 KDKA broadcast the first radio sporting event, a boxing match (Ray-Dundee). [1] April 14 NHL Championship: Ottawa Senators sweep Toronto Saint Patricks in two games. [1] April 19 25th Boston Marathon won by Frank Zuna of New Jersey in 2:18:57.6. [1] April 21 Ottawa Senators beat Vancouver Millionaires three games to two for Stanley Cup. [1] April 23 Charles Paddock runs world record 100 metre (10.4 seconds). [1] April 29 Arthur Mold British cricket bowler (1893, banished for throwing), dies. [1] April 30 American Professional Football Association reorganizes in Akron. [1] May 6 American Soccer League formed. [1] May 7 47th Kentucky Derby: Charles Thompson on Behave Yourself wins 2:04.2. [1] May 16 47th Preakness: F Coltiletti aboard Broomspun wins in 1:54.2. [1] May 30 Memorial to Captain Eddie Grant, killed in WWI, unveiled at Polo Grounds. [1] June 10 Babe Ruth becomes all time home run champion with #120 (Gavvy Cravath). [1] June 13 New York Yankees' pitcher Babe Ruth hits two home runs beating Detroit Tigers 11-8. [1] June 25 Jack Hutchinson becomes first American to win golf's British Open. [1] July 2 First million dollar gate ($1.7m) boxing match (Dempsey knocks out Carpentier). [1] July 21 Cleveland Indians (9) and New York Yankees (7) hit a record 16 doubles. [1] July 23 Edward Gourdin of the US, sets then long jump record at 25' 2 3/4". [1] August 3 Due to a technicality, eight Chicago White Sox accused in the Black Sox scandal are acquited, however Landis throws them out of baseball. [1] August 5 First radio baseball broadcast Pittsburgh Pirates-8, Philadelphia Phillies-0 (KDKA, Pittsburgh). [1] August 25 New York Yankees pitcher Harry Harper hits three batters in an inning tying record. [1] August 27 J E Clair of Acme Packing Co of Green Bay granted an NFL franchise. [1] September 27 New York Yankees beat Cleveland Indians 21-7 in Polo Grounds. [1] October 1 First all New York series to be played entirely in one stadium (the Polo Grounds) and first New York Yankees World Series begins (World Series #18). [1] October 5 First World Series radio broadcast, New York Yankees beat New York Giants 3-0 (World Series #18). [1] October 10 NFL Decatur Staleys become Chicago Staleys, win 14-10. [1] October 13 New York Giants beat New York Yankees, five games to three in 18th World Series. [1] October 16 Jim Conzelman takes over as coach of Rock Island Independents from Frank Coughlin-only mid-game coaching change in NFL history. [1] October 23 Green Bay Packers play first NFL game, 7-6 win over Minneapolis. [1] December 3 9th Canadian Football League Grey Cup: Toronto Argonauts defeats Edmonton Eskimos, 23-0. [1] December 13 Frederick Martin cricketer (14 wickets in two Tests for England 1890-92), dies. [1] December 20 American League votes to return to best-of-7 World Series, while National League votes best-of-9 Judge Kenesaw Mountain Landis casts deciding vote for best-of-7. [1]