Orioles

Atlantics

Red Stockings

Buckeyes

Hoosiers

Eclipse

Metropolitans

Athletics

Alleghenys

      Virginians

Browns

Blue Stockings

Nationals

Locations of teams for the 1884American Association season
American Association

Beaneaters

Bisons

White Stockings

Blues

Wolverines

Gothams

Quakers

   Grays

Locations of teams for the 1884National League season
National League

Mountain Citys

Monumentals

Reds

Browns*

Stogies*

Outlaw Reds

Cowboys

Brewers

       Keystones

Maroons

Saints

Nationals

Quicksteps

Locations of teams for the 1884Union Association season
Union Association
*Chicago Browns moved to Pittsburgh mid-way through the season as the Pittsburgh Stogies.

The1884 major league baseball season began on April 17, 1884. TheNational League andAmerican Association's regular seasons ended on October 15, with the Providence Grays and New York Metropolitans as theNL andAA pennant winners, respectively. The newly foundedUnion Association regular season ended on October 19, with theSt. Louis Maroons as the UA pennant winner. The postseason between the AA and NL began with Game 1 of thefirst World's Championship Series (the firstinter-league championship game of its kind in the Major Leagues) on October 23 and ended with Game 3 on October 25, in what was abest-of-five-playoff. The Grays swept the Metropolitans in three games, capturing their first World's Championship Series.

Prior to the 1884 season, in September 1883, theUnion Association was formed, in direct contravention to the reserve rule (that a ballplayer could be reserved by a team) of the 1883 National Agreement (a.k.a. Tripartite Agreement) signed between theNational League,American Association, and minor leagueNorthwestern League.^[1] In response to formation of the UA, the AA expanded their league from an eight teams to twelve teams to undermine the weak footing the UA had, as UA teams were mostly in cities that already had established AA and NL teams.^[2]

TheAmerican Association expansion saw the minor league Brooklyn Grays of theInter-State Association of Professional Baseball Clubs join as theBrooklyn Atlantics (today'sLos Angeles Dodgers) and theToledo Blue Stockings join from the minor leagueNorthwestern League, as well as the establishment of theIndianapolis Hoosiers andWashington Nationals. The latter played their last game on August 2, and were replaced by the minor leagueEastern League'sRichmond Virginians to finish Washington's schedule.

TheUnion Association was largely unstable throughout its only year in existence (though confidence in the league remained high), as three of its founding teams would not make it to the end of the season.^[2] TheAltoona Mountain Citys folded on May 31, and were replaced by the Kansas City Cowboys on June 7. ThePhiladelphia Keystones folded on August 7, and were replaced by theEastern League'sWilmington Quicksteps. TheChicago Browns relocated to Pittsburgh as thePittsburgh Stogies following their August 21 game. The Quicksteps would fold on September 15, while the Stogies would fold just three days later. On September 27, theMilwaukee Brewers and St. Paul Apostles (now renamed theSt. Paul Saints) were recruited from theNorthwestern League to finish the Philadelphia / Wilmington and Chicago/Pittsburgh schedules, respectively.

The 1884 schedule consisted of 110 games for all teams in the American Association, which had twelve active teams, and 112 games for all teams in the National League and Union Association, each of which had eight active teams. Each AA team was scheduled to play 10 games against the other eleven teams in their league, and each of NL & UA teams were scheduled to play 16 games against the other seven teams of their respective league. The National League increased its total games per team from 98 to 112, 14 games to 16 games per seven opponents. The new Union Association copied this format. Meanwhile, the American Association, expanding from eight to twelve teams, changed from the 98-game format to the 110-game format. The National League would continue to use their 112-game format through thefollowing season, while the American Association would copy the NL format.

Union Association Opening Day took place on April 17 featuring six teams, while American Association and National League Opening Days took place on May 1, featuring all twelve and all eight teams, respectively. The Union Association would see its final day of the regular season on October 19 featuring four teams, while the American Association and National League would see their final day of the regular season on October 15 featuring all twelve teams and four teams, respectively.^[3] The1884 World's Championship Series took place between October 23 and October 25.

The 1884 season saw the following rule changes:

• In the National League all restrictions on the delivery of a pitcher were removed.^[4] This lifting of restrictions enabled pitchers to throw above the shoulder during pitch delivery.^[5] The American Association would follow suit the following year.
• In the National League, six balls became abase on balls, down from seven. The American Association keeps the rule at seven balls.^[6]
• In the American Association, ahit by pitch rule was implemented, when a batter was "solidly and bodily hit by a pitched ball when he cannot apparently avoid it." The National League would not implement a hit by pitch rule until1887.^[6]

An asterisk (*) denotes the ballpark a team played the minority of their home games at
A dagger (†) denotes a team that folded mid-season
A double dagger (‡) denotes a team joined mid-season

Any team shown insmall text indicates a previous team a player was on during the season.
Any team shown initalics indicates a team a player was on from a different league. Any stat from said different league is not calculated to determine the league leader.

• 1884 Major League Baseball season schedule at Baseball Reference

• 1884 Major League Baseball season
• Major League Baseball seasons

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