Throughout the history of baseball, the rules have frequently changed as the game continues to evolve. A few common rules most professional leagues have in common is that four balls is a base on balls, three strikes is a strikeout, and three outs end a half-inning.
The Major League Baseball (MLB) season schedule consists of 162 games for each of the 30 teams in the American League (AL) and National League (NL), played over approximately six months – a total of 2,430 games, plus the postseason. The regular season runs from late March/early April to late September/early October, followed by the postseason which can run to early November. The season begins with the official Opening Day, and, as of 2018, runs 26½ weeks through the last Sunday of September or first Sunday of October. One or more International Opener games may be scheduled outside the United States or Canada before the official Opening Day. It is possible for a given team to play a maximum of 22 games in the postseason in a given year, provided the team is a wild card and advances to each of the Division Series, Championship Series, and World Series with each series going the distance.
The 2006 World Baseball Classic (WBC) was the inaugural tournament between national baseball teams that included players from Major League Baseball. It was held from March 3 to 20 in stadiums in or around Tokyo, Japan and the American cities of San Juan, Puerto Rico; Lake Buena Vista, Florida; Phoenix, Arizona; Scottsdale, Arizona; Anaheim, California; and San Diego, California.
The 2009 World Baseball Classic (WBC) was an international baseball competition. It began on March 5 and finished March 23.
Rainout, washout, rain delay, and rain stopped play are terms regarding an outdoor event, generally a sporting event, delayed or canceled due to rain, or the threat of rain. It is not to be confused with a type of out in baseball, though a baseball game can be rained out. Delays due to other forms of weather are named "snow delay", "lightning delay", "thunderstorm delay", or "fog delay", while there are many other effects of weather on sport. Also, a night game can be delayed if the floodlight system fails. Often spectators will be issued a ticket for a make up event, known as a "rain check".
In the sport of baseball, a doubleheader is a set of two games played between the same two teams on the same day. Historically, doubleheaders have been played in immediate succession, in front of the same crowd. Contemporarily, the term is also used to refer to two games played between two teams in a single day in front of different crowds and not in immediate succession.
The 2006 Little League World Series, held in South Williamsport, Pennsylvania, took place between August 18 and August 28, one day later than originally scheduled. Inclement weather forced the cancellation of the third-place game on August 27 and the postponement of the championship game also scheduled for that date. The Northern Little League of Columbus, Georgia, defeated Kawaguchi City Little League of Kawaguchi, Japan, in the championship game of the 60th Little League World Series.
The 2007 Little League World Series was a baseball tournament held August 17 through August 26 in South Williamsport, Pennsylvania. Eight teams from the United States and eight from throughout the world competed to decide the winner of the 61st installment of the Little League World Series. On August 26, the U.S. champion from Warner Robins, Georgia, defeated the international champion from Tokyo, Japan, 3–2 in 8 innings on a walk-off home run by Dalton Carriker. This was the second straight year that a team from Georgia won the championship.
A one-game playoff, sometimes known as a pennant playoff, tiebreaker game or knockout game, is a tiebreaker in certain sports—usually but not always professional—to determine which of two teams, tied in the final standings, will qualify for a post-season tournament. Such a playoff is either a single game or a short series of games.
The Southeastern Conference baseball tournament is the conference tournament in baseball for the Southeastern Conference (SEC). It is a partially double-elimination tournament and seeding is based on regular season conference records. The winner receives the conference's automatic bid to the NCAA Division I baseball tournament. The SEC Tournament champion is separate from the conference champion. The conference championship is determined solely by regular season record.
The Major League Baseball (MLB) postseason is the annual playoff tournament held to determine the champion of MLB in the United States and Canada. Since 2022, the playoffs for each league—American and National—consist of two best-of-three Wild Card Series contested by the lowest-seeded division winner and the three wild card teams, two best-of-five Division Series (LDS) featuring the wild-card winners and the two highest-seeded division winners, and finally the best-of-seven League Championship Series (LCS). The winners of the American League Championship Series (ALCS) and the National League Championship Series (NLCS) play each other in the best-of-seven World Series. Under this system, the postseason comprises 32 to 53 games. The postseason tournament takes place after the conclusion of MLB's regular season and takes approximately one month to complete.
In the sixth season of the Balkan International Basketball League, ten participants from Bulgaria, the Republic of Macedonia, Montenegro, Israel and Romania and the new represented country Kosovo has competed.
The 2015–16 National League 2 North is the seventh season of the fourth tier of the English domestic rugby union competitions since the professionalised format of the second division was introduced. There was talk of this being the last season in this format due to RFU changes to tier four which were supposed to result in a restructuring of the league from two regional divisions to three for the 2016–17 season but this seems to have been put on hold due to protests from the northern clubs who stood to lose revenue from a smaller fixture list.
The Northern and Southern Cups are the two major regional quidditch tournaments of the United Kingdom. Organised by QuadballUK, the tournaments serve both as qualification prerequisites for other tournaments, such as the European Quidditch Cup and the British Quidditch Cup alongside being their own stand alone tournaments. Regionals are often considered the most important tournaments of the year after the British Quidditch Cup and they serve as qualifiers for the latter tournament. Those teams that fail to qualify for BQC each season compete in the Development Cup instead. From 2021 onwards the tournaments have been held as a series of one-day fixtures exclusively for university teams with the equivalent Community League tournament held for community teams.
The Triple-A Classic was an interleague postseason championship series held annually between the league champions of the American Association (AA) and International League (IL) Triple-A leagues of Minor League Baseball from 1988 to 1991.
The 2017–18 European Rugby Challenge Cup was the fourth edition of the European Rugby Challenge Cup, an annual second-tier rugby union competition for professional clubs. It was also the 22nd season of the Challenge Cup competition in all forms, following on from the now defunct European Challenge Cup. Clubs from six European nations plus two Russian club competed for the title.
The 2017–18 National League 2 North is the ninth season of the fourth tier (north) of the English domestic rugby union competitions since the professionalised format of the second division was introduced.
The 2021 Scotties Tournament of Hearts, Canada's national women's curling championship, was held from February 19 to 28 at the Markin MacPhail Centre at Canada Olympic Park in Calgary, Alberta. The winning Kerri Einarson team represented Canada at the 2021 World Women's Curling Championship. The world championship was supposed to be held at the Curlinghalle Schaffhausen in Schaffhausen, Switzerland; however, the event was cancelled and rescheduled to the "Calgary bubble" of the Markin MacPhail Centre.
The 2021–22 EPCR Challenge Cup pool stage was the first stage of the competition in what was the eighth season of the EPCR Challenge Cup. The competition involved fifteen teams competing across three pools of five teams, for ten last 16 places. The three highest-ranked clubs from each pool and the highest-ranked fourth-placed club, joined the three clubs ranked 9 to 11 from each of the Heineken Champions Cup pools, in the Round of 16. The pool stage began on 10 December 2021 and was completed on 10 April 2022.
OH 2 
MA 3◄ 
GA 9◄
OR 4 
MD 6
AZ 16◄
TX 6◄ 
MN 0
CUR 3 
JPN 10◄ 
SAU 5 
CAN 13◄ 
VEN 2◄ 
TWN 1 
MEX 11◄ 
NED 1 (F/4)