Most team sports have a period of training to recover fitness levels, followed by exhibition games (commonly known as friendlies outside North America) 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, the scheduling is different. Rather than every team playing all others twice, teams usually 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, and to only have 2 common opponents in a season. 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 major 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 a 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. The term "home and away season" is sometimes used instead of regular season.
Many 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 five times since 1975, with the two most recent examples occurring in 1996 and 2013–14. 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 five major U.S. sports leagues (Super Bowl, World Series, NBA Finals, Stanley Cup Finals, and MLS Cup) and the major Australian sports (AFL Grand Final, NRL Grand Final, NBL Grand Final and A-League Grand Final).
European leagues have also started holding playoffs after a double round-robin "regular season". The Football League started its promotion playoffs 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 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 both the cup winner and runner-up are already qualified for Europe by other means). 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. Conversely, some leagues like the Premier League do not hold a postseason, and therefore these leagues' champions and relegation are instead based on the regular season records.
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, first used more than one round of playoffs in 1893, and has continuously operated a playoff system (except during the two World Wars) since 1899. 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.
- "E" denotes exhibition games.
- "Q" denotes pre-competition qualifiers.
- "S" denotes the start of the regular-season.
- "P" denotes playoff(s)/postseason/knockout stages.
- "F" denotes Final(s).
- A team from Andorra, BC Andorra, has competed in the league since the 2014–15 season.
- Replaced the former European club competition, the Heineken Cup, effective in 2014–15.
- 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.
- The league originally involved only the three Celtic nations; Italy joined beginning in the 2010–11 season.
- Since the 2015 season, the only series race held outside the U.S. is hosted by Canada. Australia, Brazil, and Japan have hosted races in the past.
- As of the current 2014–15 season, there are 22 teams in Russia and one each in Belarus, Croatia, Finland, Kazakhstan, Latvia, and Slovakia. A team from Ukraine is on hiatus due to the ongoing conflict in the country's east. A team from China is expected to join the league in 2016–17.
- Like many 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.
- The Serie del Rey usually ends in September.
- 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. Since 2013, two of its majors, one in the UK and the other in France, have been 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 World Series usually ends in late October, but can extend into early November.
- Since the 2013 season, the top two NASCAR touring series, the Sprint Cup and Xfinity Series, race only in the US. The third-level Truck Series has a race in Canada. The Xfinity Series has previously held races in Canada and Mexico. NASCAR also operates national series in Canada and Mexico and a European series, plus many regional developmental series in the US.
- The 2016 season is the first in which NASCAR will use a playoff-style system in all three national touring series. Before then, only the Sprint Cup Series used a playoff-style system, culminating in the 10-race Chase for the Sprint Cup.
- The NFL currently takes at least one regular-season game outside the US (London since 2007). The Jacksonville Jaguars are in the middle of a four-year period (2013–2016) in which one home game is in London. For several years in the early 21st century, the Buffalo Bills played one home game per season in Toronto.
- The NCAA has never recognized an official champion in the top-level Division I FBS. Although the four-team College Football Playoff began in 2014, it is not an official NCAA championship event. All other NCAA divisions determine officially recognized champions in playoff tournaments that start in November. The playoffs in Divisions II and III end in December. Since the 2010 season, the Division I FCS playoffs end in January.
- The vast majority of the PGA Tour's sole-sanctioned events are in the US proper, but the tour also has events in Malaysia, 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.
- The current 2015–16 season features one team from Wales in Swansea City, which has been in the league since the 2011–12 season.
- In 2015, Argentina abandoned its traditional Apertura and Clausura format in favor of an expanded single league season. In 2016, there will be a truncated season in the first half of the year, followed by a change to an August–June season for 2016–17 and beyond.
- Argentine and Japanese teams joined the competition in 2016. The Japanese team divides its "home" matches between Tokyo and Singapore.
- 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 begin in July.
- In non-World Cup years, the final match is 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. Bahrain, China, the United Arab Emirates, and the USA 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, the WNBA Finals run into late October. In non-Summer Olympic years, the WNBA Finals end in early October.
|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 women's and 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 late August, with finals series extending up to late September or early October.|
|Baseball||April to early October, with playoffs extending up to early November. The Australian Baseball League runs from November to early February, with playoffs extending up to late February.|
|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 late October, with playoffs extending into 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. The three major exceptions to this rule are:
|Motor racing||Year-round, but generally concentrated from March to October. NASCAR runs from mid-February to late September, with playoffs extending up to late November.|
|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. In Australia, the domestic competition does not overlap at all with Super Rugby, instead beginning in August and ending in early November.|