In an organized sports league, a season is the portion of one year in which regulated games of the sport are in session. For example, in Major League Baseball, one season lasts approximately from April 1 to October 1; in Association football, it is generally from August until May (although in some countries, especially those in Scandinavia and North America, the season starts in the spring and finishes in the autumn, due either to weather conditions encountered during the winter or to limit conflict with locally more popular football codes).
A year can often be broken up into several distinct sections (sometimes themselves called seasons). These are: a preseason, a series of exhibition games played for training purposes; a regular season, the main period of the league's competition; the postseason, a playoff tournament played against the league's top teams to determine the league's champion; and the offseason, the time when there is no official competition.
Most team sports have a period of training to recover fitness levels, followed by exhibition games (commonly known as "friendlies" in football (soccer) lexicon) prior to the start of their regular seasons ("pre-season training" and "pre-season" games). The game results do not count in the season standings of the teams, so they serve conveniently to test player candidates and to practice teamwork under game conditions. They may be used to promote the team effectively both at home and elsewhere. For some teams a pre-season overseas tour may be profitable, even lucrative. For some leagues, overseas games may promote their sport or their league to new audiences.
In some sports there may be a pre-season curtain-raiser or "supercup" competition—for example, in England, the previous season's winners of the FA Cup and Premier League play one another for the Community Shield before the start of the regular season. Part of the profits from this game are divided up amongst all teams participating in both competitions the year before, to donate to charities and good causes in their local area while the rest is given to national charities and good causes by The FA itself.
In almost every sport, the term "regular season" refers to the sport's league competition. The regular season is usually similar to a group tournament format: teams are divided into groups, conferences or divisions, and each club plays a set number of games against a set number of opponents. In most countries the league is played in a double round-robin format, where every team plays every other team twice, once at their home venue, and once away at the oppositions venue as visitors. The results over all games are accumulated and when every team has completed its full schedule of games, a winner is declared.
In North America, this may be in part due to the unusual way in which that region's sports leagues are scheduled. Rather than every team playing all others twice, teams may play more games against local rivals than teams in other parts of the country. For example, the NBA's Los Angeles Lakers will play the Los Angeles Clippers (a team within their division, a subdivision of the conference) four times in a regular season, while both will only play the Boston Celtics, who are in the opposite Eastern Conference, twice. Part of this is due to the vast geographic distances between some teams in North America—measured in a straight line Los Angeles is 2,606 miles (4,194 kilometers) from Boston, for instance—and a desire to limit travel expenses. In the scheduling system used in the NFL, it is possible for two teams to only meet every four years. Major League Baseball has the most uneven schedules of all the four major North American sports. In MLB the conferences are called leagues instead, but have exactly the same effect as conferences (as with all North American sports leagues, leagues, conferences and division are not based on skill, but instead geography, history and rivalries). Teams play 19 games against each of teams in their own division each year but will only play 20 games total against all of the teams in the other league. Because each of the interleague matchups is part of a 3-game series or s 2-game series, teams will play no games at all against most teams from the other league. They play 6 of the 15 teams in the other league
In Australia, the two largest football leagues, the AFL (Australian rules football) and NRL (rugby league), both grew out of competitions held within a single city (respectively Melbourne and Sydney) and only began expanding to the rest of the country when inexpensive air travel made a national league possible. These leagues use a single table instead of being split into divisions.
Many association football leagues in Latin America have a very different system. Because most Latin American countries never had a football cup competition, they instead split their season into two parts, typically known as the Apertura and Clausura (Spanish for "opening" and "closing"). Most countries that use this system, Argentina being one notable example, crown separate league champions for each part of the season, using only league play. A few others, such as Uruguay, crown one champion at the end of a playoff involving top teams from each half of the season. Mexico operates its Apertura and Clausura as separate competitions that both end in playoffs.
A system similar to the Apertura and Clausura developed independently in Philippine professional basketball, with formerly two, now three tournaments (called "conferences") in one season, with each conference divided into an "elimination round" (the regular season) and the playoffs in the North American sense. Winning the playoffs is the ultimate goal of every team for every conference; while there is no season championship, winning all conferences within a single season is rare and has only happened four times 1975, and has not happened since 1996. The elimination round and playoffs setup has permeated down to the local level and in most team sports, although seasons are not divided into conferences.
Many sports leagues have playoffs or "finals" that occur after the regular season is complete. A subset of the teams enter into a playoff tournament, usually a knockout tournament, generally a pre-determined number with better overall records (more wins, fewer losses) during the regular season. There are many variations used to determine the champion, the league's top prize. In many of these leagues, winning the league's top prize at the conclusion of the postseason is more important than winning the regular season. This includes the four major U.S. sports leagues (Super Bowl, World Series, NBA Finals and Stanley Cup) and the major Australian sports (AFL Grand Final, NRL Grand Final and A-League Grand Final).
European leagues have also started holding playoffs (called "play-offs") after a double round-robin "regular season". The Football League started its promotion play-offs in 1987, with the third up to the sixth-ranked teams participating for the final promotion berth (the two top teams are automatically promoted). Elsewhere, relegation playoffs are also held to determine which teams would be relegated to the lower leagues. One prominent top-level association football league, the Eredivisie of the Netherlands, uses two different playoffs—one for relegation purposes, and the other to determine one of the league's entrants in the following season's UEFA Europa League. In Superleague Greece, which currently has two places in the UEFA Champions League and three in the Europa League, the teams that finish second through fifth in the regular season enter a home-and-away "playoff" mini-league. Since one Europa League place is reserved for the country's cup winner, only three of the four teams are guaranteed a place in the next season's European competitions, unless one of the playoff participants is already qualified for Europe. The playoff determines the country's second Champions League participant, and the points at which the two or three Europa League entrants join that competition.
Although rugby union did not become professional until 1995, that sport has a long history of playoffs, primarily in France and the Southern Hemisphere. The French national championship, now known as Top 14, staged a championship final in its first season of 1892, and has done so continuously (except during the two World Wars) since 1899. France first used multiple rounds of playoffs in 1920. South Africa's Currie Cup has determined its champions by playoffs since 1968, and New Zealand's National Provincial Championship, the top level of which is now known as the ITM Cup, has used playoffs since its creation in 1976. Argentina's Nacional de Clubes has determined its champion by playoffs since its inception in 1993. Currently, two separate competitions feed into the Nacional, the Torneo de la URBA (for Buenos Aires clubs, held since 1899) and Torneo del Interior (for the rest of the country); both use playoffs to determine their champions. Super Rugby, involving regional franchises from Australia, New Zealand, and South Africa, has used playoffs to determine its champions since its creation as Super 12 in 1996.
By contrast, other European countries were slow to adopt playoffs in rugby union. The English Premiership only began playoffs in 1999–2000, and did not use them to determine the league champion until 2002-03. The Celtic League, now known as Pro12, resisted a playoff system even longer; its champions were determined solely by league play from its inception in 2001–02 until playoffs began in 2009–10.
When the UEFA Champions League reformatted in 1993, it added a "knockout stage" involving four teams that finished at the top two places in their respective groups. Like North American sports leagues, this setup prevented some participants from facing each other, necessitating a two-round knockout stage to determine the champions. It has since been expanded to the 4-round knockout stage today. The Copa Libertadores has applied a knockout stage since the 1988 tournament, expanding to the current four-round format next season. All intercontinental club football competitions now feature a knockout stage.
The off-season, vacation time, or close season is the time of year when there is no official competition. Although upper management continues to work, the athletes will take much vacation time off. Also, various events such as drafts, transfers and important off-season free agent signings occur. Generally, most athletes stay in shape during the off-season in preparation for the next season. Certain new rules in the league may be made during this time, and will become enforced during the next regular season.
As most countries which have a league in a particular sport will operate their regular season at roughly the same time as the others, international tournaments may be arranged during the off season.
For example, most European football league club competitions run from July or August to May, subsequently major international competitions such as the FIFA World Cup and UEFA European Football Championship are organised to occur in June and July.
Seasons by league
The table represents typical seasons for some leagues by month. Blank or white denotes off-season and pre-season months and solid colors mark the rest of the year. Leagues in the same sport use the same color.
- "Q" denotes pre-competition qualifiers
- "S" denotes the start of the regular-season.
- "P" denotes playoff(s)/postseason/knockout stages.
- "F" denotes Final(s).
- The current scheduling, in which the season starts in January, took effect in 2012. In 2010 and 2011, the schedule began late in the previous calendar year.
- The bulk of the tour's sole-sanctioned events are in Europe, with some in the Persian Gulf countries. It co-sanctions many other events with tours in Asia, Africa, and Australia. Along with the PGA Tour, the European Tour co-sanctions the major championships and the World Golf Championships; one of the majors is held in the UK, one of the WGC events is held in China, and the rest of these events are in the US. A new WGC event in South Africa was to be launched in 2012, but has been delayed.
- The 2009 season was played in South Africa because of security issues related to the Indian general elections scheduled for the same time as the league.
- Two races are held in Canada and one in Brazil. A race in China was added in 2012, replacing a former race in Japan.
- As of the upcoming 2013–14 season, there will be 21 teams in Russia and one each in Belarus, Croatia, the Czech Republic, Kazakhstan, Latvia, Slovakia and Ukraine.
- Like many association football leagues in Latin America, Mexico divides its season into two phases with separate champions in each phase. Unlike most leagues in that sport, Liga MX uses a knockout playoff, involving the top eight teams after league play, to determine its champions.
- Most LPGA events are held in the US, but it also sole-sanctions official money events in Thailand, Singapore, Mexico, China, Canada, Malaysia, and Taiwan, as well as an unofficial event in Brazil. As of 2013, two of its majors, one in the UK and the other in France, are co-sanctioned with the Ladies European Tour. The LPGA also co-sanctions events with the Korean LPGA and Japan LPGA in those countries and the ALPG Tour in Australia.
- The top-level Sprint Cup Series and third-level Camping World Truck Series race only in the US. The second-level Nationwide Series has one race in Canada, and previously had a race in Mexico. NASCAR also operates many regional developmental series in the US, and national series in Canada and Mexico.
- NASCAR uses a playoff-style system only in the Sprint Cup Series. The bulk of the Cup Series season is used to determine the 12 drivers who qualify to contend for the season title in a 10-race finale known as the Chase for the Sprint Cup. In all other NASCAR series, the season is contested as a unified whole, with all races counting equally toward determining the series champion.
- The Buffalo Bills play one annual regular-season home game in Toronto, and the NFL currently takes at least one other regular-season game outside the US (London since 2007).
- The top-level Division I FBS does not use a playoff, instead using a series of bowl games beginning in December and culminating in the Bowl Championship Series in early January. All other NCAA divisions determine their champions on the field in a playoff tournament that starts in November. The playoffs in Divisions II and III end in December. Since the 2010 season, the Division I FCS playoffs end in January.
- Almost all of the PGA Tour's sole-sanctioned events are in the US proper, but the tour also has events in Mexico, Canada, and Puerto Rico. Along with the European Tour, the PGA Tour co-sanctions the major championships and the World Golf Championships; one of the majors is held in the UK, one of the WGC events is held in China, and the rest of these events are in the US. A new WGC event in South Africa was to be launched in 2012, but has been delayed.
- The PGA Tour has announced major scheduling changes for 2013 and beyond. The 2013 season will be the last held within a calendar year. The 2014 season, and later seasons, will start in October of the previous calendar year, shortly after the Tour Championship.
- The upcoming 2013–14 season will feature two teams from Wales—Swansea City, which has been in the league since the 2011–12 season, and newly promoted Cardiff City.
- Like many association football leagues in Latin America, Argentina divides its season into two phases with separate champions in each phase. Champions are determined at the end of league play in each phase.
- Italy joined beginning in the 2010–11 season.
- The playoffs, or "finals" as they are officially called, begin in late June in Rugby World Cup years.
- During World Cup years, the final match is held in July; in other years, the finals will begin in July.
- In non-World Cup years, the final match will be held in August.
- Depending on the calendar, the final may fall on the last weekend of May in some seasons.
- Currently, one race is held in New Zealand and one in the USA. Bahrain, China, and the United Arab Emirates have staged races in the past. Longer-term plans call for additional races in Hong Kong, India, the Philippines, Singapore, South Africa, and South Korea.
- During Summer Olympic years
|American football||August to December, playoffs from January to early February. College bowl games from December to January. Indoor football, past professional leagues such as the USFL and XFL, and some amateur leagues play in the February to August season.|
|Association football||Usually August to May in the Northern Hemisphere, and February to November in the Southern Hemisphere. Exceptions are generally for one of two reasons:
(See Domestic association football season for details.)
|Australian rules football||March to October|
|Baseball||April to early October, with postseason extending up to early November.|
|Basketball||In most countries, late October to mid-April, with playoffs extending up to mid-June. The three major exceptions to this rule are:
|Canadian football||July to November|
|Cricket||Year-round. Domestic seasons typically held in the driest period of the year—summer in temperate climates, dry season in tropical climates.|
|Ice hockey||Early October to mid-April, with playoffs extending up to early June.|
|Motor racing||Year-round, but generally concentrated from March to October.|
|Rugby league||Late February to October in both the Northern and Southern Hemispheres.|
|Rugby union||September to late May, sometimes the first weekend in June, in the Northern Hemisphere. In the Southern Hemisphere, Super Rugby starts in February and ends in early July in World Cup years and mid-August in other years. Domestic competitions in New Zealand and South Africa overlap slightly with the Super Rugby season, starting in July and ending in October or November.|